Image of the interacting galaxy pair NGC 5394/5 obtained with NSF’s National Optical-Infrared Astronomy Research Laboratory’s Gemini North 8-meter telescope on Hawai’i’s Maunakea using the Gemini Multi-Object Spectrograph in imaging mode. This four-color composite image has a total exposure time of 42 minutes. Credit: International Gemini Observatory/NOIRLab/NSF/AURA
Comet-like stars This spectacular Picture of the Week was produced from data gathered by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, combined with data from the NASA/ESA Hubble Space Telescope. It shows a cluster of stars named Westerlund 1, one of the most massive young star clusters known to reside in the Milky Way. Excitingly, it also shows the comet-like “tails” of material stretching away from some of the giant stars in Westerlund 1. Such tails are formed in the thick, relentless winds that pour from the cluster’s stellar residents, carrying material outwards. This phenomenon is similar to how comets get their famous and beautiful tails. Comet tails in the Solar System are driven away from the nucleus of their parent comet by a wind of particles that streams out from the Sun. Consequently comet tails always point away from our Sun. Similarly, the tails of the huge red stars shown in this image point away from the core of the cluster, likely the result of powerful cluster winds generated by the hundreds of hot and massive stars found towards the centre of Westerlund 1. These massive structures cover large distances and indicate the dramatic effect the environment can have on how the stars form and evolve. These comet-like tails were detected during an ALMA study of Westerlund 1 that aimed to explore the cluster’s constituent stars and figure out how, and at what rate, they lose their mass. The cluster is known to host a large amount of massive stars, many of them intriguing and rare types, making it of great interest and use to astronomers wishing to understand the myriad stars in our galaxy. Credit: ESO/D. Fenech et al.; ALMA (ESO/NAOJ/NRAO)
Nicknamed the Southern Pinwheel, Messier 83 (or NGC 5236) is a stunning face-on spiral galaxy located about 15 million light-years away in the southern constellation of Hydra. Its spiral arms are lined with dark lanes of dust and peppered with reddish, star-forming clouds of hydrogen gas. One of the deepest images ever taken of the Southern Pinwheel (combining more than 11 hours of exposure time), this view was captured with the Dark Energy Camera (DECam), which was built by the US Department of Energy (DOE) and is mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. Numerous background galaxies, which lie much farther away than Messier 83, appear around the edges of the image. Credit: CTIO/NOIRLab/DOE/NSF/AURA Acknowledgment: M. Soraisam (University of Illinois) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Stellar Snowflakes / Almost like snowflakes, the stars of the globular cluster NGC 6441 sparkle peacefully in the night sky, about 13 000 light-years from the Milky Way’s galactic centre. Like snowflakes, the exact number of stars in such a cluster is difficult to discern. It is estimated that together the stars weigh 1.6 million times the mass of the Sun, making NGC 6441 one of the most massive and luminous globular clusters in the Milky Way. NGC 6441 is host to four pulsars that each complete a single rotation in a few milliseconds. Also hidden within this cluster is JaFu 2, a planetary nebula. Despite its name, this has little to do with planets. A phase in the evolution of intermediate-mass stars, planetary nebulae last for only a few tens of thousands of years, the blink of an eye on astronomical timescales. There are about 150 known globular clusters in the Milky Way. Globular clusters contain some of the first stars to be produced in a galaxy, but the details of their origins and evolution still elude astronomers. Credit: ESA/Hubble & NASA, G. Piotto
A 50-trillion-km (33-trillion-mile, or 5 light-year) long section of the western wall in the Carina Nebula, as observed with adaptive optics on the Gemini South telescope. This mountainous section of the nebula reveals a number of unusual structures including a long series of parallel ridges that could be produced by a magnetic field, a remarkable almost perfectly smooth wave, and fragments that appear to be in the process of being sheared off the cloud by a strong wind. There is also evidence for a jet of material ejected from a newly-formed star. The exquisite detail seen in the image is in part due to a technology known as adaptive optics, which resulted in a ten-fold improvement in the resolution of the research team’s observations. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Acknowledgment: PI: Patrick Hartigan (Rice University) Image processing: Patrick Hartigan (Rice University), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Two Supernovae, One Galaxy / Approximately 85 million light-years from Earth, in the constellation of Libra, is the beautiful galaxy NGC 5861, captured here by the NASA/ESA Hubble Space Telescope. NGC 5861 is an intermediate spiral galaxy. Astronomers classify most galaxies by their morphology. For example, the Milky Way galaxy is a barred spiral galaxy. An intermediate spiral galaxy has a shape lying in between that of a barred spiral galaxy, one that appears to have a central bar-shaped structure, and that of an unbarred spiral galaxy, one without a central bar. Two supernovae, SN1971D and SN2017erp, have been observed in the galaxy. Supernovae are powerful and luminous explosions that can light up the night sky. The brightest supernova ever recorded was possibly SN 1006. It shone 16 times as bright as Venus from April 30 to May 1, 1006 AD. Credit: ESA/Hubble & NASA, A. Riess et al.
Caption: The Daniel K. Inouye Solar Telescope has produced the highest resolution image of the Sun’s surface ever taken. In this picture taken at 789nm, we can see features as small as 30km (18 miles) in size for the first time ever. The image shows a pattern of turbulent, “boiling” gas that covers the entire sun. The cell-like structures – each about the size of Texas – are the signature of violent motions that transport heat from the inside of the sun to its surface. Hot solar material (plasma) rises in the bright centers of “cells,” cools off and then sinks below the surface in dark lanes in a process known as convection. In these dark lanes we can also see the tiny, bright markers of magnetic fields. Never before seen to this clarity, these bright specks are thought to channel energy up into the outer layers of the solar atmosphere called the corona. These bright spots may be at the core of why the solar corona is more than a million degrees! This image covers an area 8,200 × 8,200 km (5,000 × 5,000 miles, 11 × 11 arcseconds). Credit: NSO/AURA/NSF
This stunning image features NGC 3198, a galaxy that lies about 47 million light-years away in the constellation Ursa Major. This image was taken with the Mosaic instrument on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, and shows the full extent of the galaxy, from the bright central bulge to the tenuous outer reaches of the tightly-wound spiral arms. Almost all the objects lurking in the background are galaxies or galaxy clusters — a sea of distant galaxies of all shapes, sizes, and orientations. Accurately measuring the distance to an astronomical object — everything from our own Sun to galaxies such as NGC 3198 — is an age-old challenge for astronomers, and requires a combination of measurements and methods. The galaxy at the heart of this image has played a part in this astronomical undertaking by allowing astronomers to calibrate astronomical distance measurements based on a type of variable star known as a Cepheid variable. Credit: KPNO/NOIRLab/NSF/AURA. Acknowledgments: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
This image showing the entire disk of Jupiter in infrared light was compiled from a mosaic of nine separate pointings observed by the international Gemini Observatory, a program of NSF’s NOIRLab on 29 May 2019. From a “lucky imaging” set of 38 exposures taken at each pointing, the research team selected the sharpest 10%, combining them to image one ninth of Jupiter’s disk. Stacks of exposures at the nine pointings were then combined to make one clear, global view of the planet. Even though it only takes a few seconds for Gemini to create each image in a lucky imaging set, completing all 38 exposures in a set can take minutes — long enough for features to rotate noticeably across the disk. In order to compare and combine the images, they are first mapped to their actual latitude and longitude on Jupiter, using the limb, or edge of the disk, as a reference. Once the mosaics are compiled into a full disk, the final images are some of the highest-resolution infrared views of Jupiter ever taken from the ground. Credit: International Gemini Observatory/NOIRLab/NSF/AURA, M.H. Wong (UC Berkeley) and team Acknowledgments: Mahdi Zamani
This stunning image by the NASA/ESA Hubble Space Telescope features the spiral galaxy NGC 5643 in the constellation of Lupus (The Wolf). Looking this good isn’t easy; thirty different exposures, for a total of 9 hours observation time, together with the high resolution and clarity of Hubble, were needed to produce an image of such high level of detail and of beauty. NGC 5643 is about 60 million light-years away from Earth and has been the host of a recent supernova event (not visible in this latest image). This supernova (2017cbv) was a specific type in which a white dwarf steals so much mass from a companion star that it becomes unstable and explodes. The explosion releases significant amounts of energy and lights up that part of the galaxy. The observation was proposed by Adam Riess, who was awarded a Nobel Laureate in physics 2011 for his contributions to the discovery of the accelerating expansion of the Universe, alongside Saul Perlmutter and Brian Schmidt. Credit: ESA/Hubble & NASA, A. Riess et al. Acknowledgement: Mahdi Zamani
This observation from the SMARTS 0.9-meter Telescope at Cerro Tololo Inter-American Observatory shows the result of a truly spectacular galactic collision. The elliptical galaxy NGC 5291 — the hazy oval cloud at the center of this image — was struck by a careening rogue galaxy over 300 million years ago. The aftermath of this cataclysmic collision is a ring of galactic debris — visible as the tenuous luminous clouds spreading left and right from the golden oval of NGC 5291. This image also shows more gentle galactic interactions — NGC 5291 is interacting sedately with the unusually curved galaxy to the right of it, which is known as the Seashell. Credit: CTIO/NOIRLab/NSF/AURA Acknowledgments: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
In the heart of the Crab Nebula (Messier 1) a neutron star is rotating 30 times every single second. This pirouetting star, known as the Crab Pulsar, consists purely of neutrons, and has an intense magnetic field which ejects jets of material from its poles at nearly the speed of light. The Crab Pulsar has a mass about one and a half times that of our Sun, yet all this mass is packed into a sphere only 28 km (17 miles) in diameter — roughly the size of Mars’s small moon Phobos. The wispy structures shown in this image are caused by material flowing equatorially outwards from the pulsar and careening into the surrounding nebula. These dynamic features, known as termination shocks, move and change shape as outflow from the puslar ebbs and flows. This changeability is showcased by this composite image, which is a compilation of three Gemini North observations taken over a 5-year period at the same infrared wavelength: observations from October 2009 are shown in blue and observations from December 2014 are shown in red. This color coding of the observations produces a striking rainbow effect highlighting the high speed motion of the termination shocks, which have noticeably changed position between observations. Gemini North on Maunakea, Hawai‘i, is one of the pair of telescopes that make up the international Gemini Observatory, a Program of NSF’s NOIRLab. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Acknowledgments: Image processing: Jen Miller (Gemini Observatory/NSF's NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
KPNO captures irregular starburst galaxy IC 10 in glorious detail This striking image from NOIRLab’s Kitt Peak National Observatory (KPNO) presents a portrait of the irregular galaxy IC 10, a disorderly starburst galaxy close to the Milky Way. As well as a population of bright young stars, this irregular galaxy harbors exotic Wolf-Rayet stars and a black hole. IC 10 lies around 2 million light-years from Earth in the direction of the constellation of Cassiopeia. Though this distance seems huge, it puts IC 10 in the ever-growing Local Group of galaxies. Credit: KPNO/NOIRLab/NSF/AURA Data obtained and processed by: P. Massey (Lowell Obs.), G. Jacoby, K. Olsen, & C. Smith (NOAO/AURA/NSF) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The emission nebula Sh2-54 glows brightly in this image from the SMARTS 0.9-meter Telescope at Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab. Gathering the fine details of this particular image required almost twenty minutes of observations and three different wavelength filters. Situated within the constellation of Serpens (The Serpent), Sh2-54 forms part of a much wider nebulosity which includes the famous Eagle Nebula. Serpens is a unique constellation, the only one of the official 88 used today that is split into two unconnected parts: Serpens Caput — the Serpent’s Head — and Serpens Cauda — The Serpent’s Tail. Credit: CTIO/NOIRLab/NSF/AURA Acknowledgment: Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Pictured here is the captivating galaxy NGC 2525. Located nearly 70 million light-years from Earth, this galaxy is part of the constellation of Puppis in the southern hemisphere. Together with the Carina and the Vela constellations, it makes up an image of the Argo from ancient greek mythology. Another kind of monster, a supermassive black hole, lurks at the centre of NGC 2525. Nearly every galaxy contains a supermassive black hole, which can range in mass from hundreds of thousands to billions of times the mass of the Sun. Hubble has captured a series of images of NGC2525 as part of one of its major investigations; measuring the expansion rate of the Universe, which can help answer fundamental questions about our Universe’s very nature. ESA/Hubble has now published a unique time-lapse of this galaxy and it’s fading supernova. Credit: ESA/Hubble & NASA, A. Riess and the SH0ES team Acknowledgment: Mahdi Zamani
An isolated neutron star in the Small Magellanic Cloud An isolated neutron star in the Small Magellanic Cloud This new picture created from images from telescopes on the ground and in space tells the story of the hunt for an elusive missing object hidden amid a complex tangle of gaseous filaments in one of our nearest neighbouring galaxies, the Small Magellanic Cloud. The reddish background image comes from the NASA/ESA Hubble Space Telescope and reveals the wisps of gas forming the supernova remnant 1E 0102.2-7219 in green. The red ring with a dark centre is from the MUSE instrument on ESO’s Very Large Telescope and the blue and purple images are from the NASA Chandra X-Ray Observatory. The blue spot at the centre of the red ring is an isolated neutron star with a weak magnetic field, the first identified outside the Milky Way. Credit: ESO/NASA, ESA and the Hubble Heritage Team (STScI/AURA)/F. Vogt et al.
Moving heart of the Crab Nebula / While many other images of the famous Crab Nebula have focused on the filaments in the outer part of the nebula, this image shows the very heart of the Crab Nebula including the central neutron star — it is the rightmost of the two bright stars near the centre of this image. The rapid motion of the material nearest to the central star is revealed by the subtle rainbow of colours in this time-lapse image, the rainbow effect being due to the movement of material over the time between one image and another. Credit: NASA, ESA
The closest star system to the Earth is the famous Alpha Centauri group. Located in the constellation of Centaurus (The Centaur), at a distance of 4.3 light-years, this system is made up of the binary formed by the stars Alpha Centauri A and Alpha Centauri B, plus the faint red dwarf Alpha Centauri C, also known as Proxima Centauri. The NASA/ESA Hubble Space Telescope has given us this stunning view of the bright Alpha Centauri A (on the left) and Alpha Centauri B (on the right), flashing like huge cosmic headlamps in the dark. The image was captured by the Wide Field and Planetary Camera 2 (WFPC2). WFPC2 was Hubble’s most used instrument for the first 13 years of the space telescope’s life, being replaced in 2009 by WFC3 during Servicing Mission 4. This portrait of Alpha Centauri was produced by observations carried out at optical and near-infrared wavelengths. Compared to the Sun, Alpha Centauri A is of the same stellar type G2, and slightly bigger, while Alpha Centauri B, a K1-type star, is slightly smaller. They orbit a common centre of gravity once every 80 years, with a minimum distance of about 11 times the distance between the Earth and the Sun. Because these two stars are, together with their sibling Proxima Centauri, the closest to Earth, they are among the best studied by astronomers. And they are also among the prime targets in the hunt for habitable exoplanets. Using the HARPS instrument astronomers already discovered a planet orbiting Alpha Centauri B. 24 August 2016 astronomers announced the discovery of an Earth-like planet in the habitable zone orbiting the star Proxima Centauri. Credit: ESA/Hubble & NASA
The Silver Sliver Galaxy — more formally known as NGC 891 — is shown in this striking image from the Mosaic instrument on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. NGC 891 is a spiral galaxy that lies almost perfectly edge-on to us, leading to its elongated appearance and its striking resemblance to our home galaxy, the Milky Way, as seen from the Earth. Since NGC 891 is oriented edge-on, it’s great for investigating the galactic fountain model. When stellar winds and supernovae from the disk of a galaxy eject gas into the surrounding medium, it can create condensation that rains back down onto the disk. The condensed gas then provides new fuel for star formation. In addition to the portrait of NGC 891, this image is littered with astronomical objects near and far — bright foreground stars from our own galaxy intrude upon the view of NGC 891 and distant galaxies lurk in the background. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgements: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The Dumbbell Nebula — also known as Messier 27 or NGC 6853 — is a typical planetary nebula and is located in the constellation Vulpecula (The Fox). The distance is rather uncertain, but is believed to be around 1,200 light-years. It was first described by the French astronomer and comet hunter Charles Messier who found it in 1764 and included it as no. 27 in his famous list of extended sky objects  .Despite its class, the Dumbbell Nebula has nothing to do with planets. It consists of very rarified gas that has been ejected from the hot central star (well visible on this photo), now in one of the last evolutionary stages. The gas atoms in the nebula are excited (heated) by the intense ultraviolet radiation from this star and emit strongly at specific wavelengths. This image is the beautiful by-product of a technical test of some FORS1 narrow-band optical interference filtres. They only allow light in a small wavelength range to pass and are used to isolate emissions from particular atoms and ions. In this three-colour composite, a short exposure was first made through a wide-band filtre registering blue light from the nebula. It was then combined with exposures through two interference filtres in the light of double-ionized oxygen atoms and atomic hydrogen. They were colour-coded as “blue”, “green” and “red”, respectively, and then combined to produce this picture that shows the structure of the nebula in “approximately true” colours. They are three-colour composite based on two interference ([OIII] at 501 nm and 6 nm FWHM — 5 min exposure time; H-alpha at 656 nm and 6 nm FWHM — 5 min) and one broadband (Bessell B at 429 nm and 88 nm FWHM; 30 sec) filtre images, obtained on September 28, 1998, during mediocre seeing conditions (0.8 arcsec). The CCD camera has 2048 x 2048 pixels, each covering 24 x 24 µm and the sky fields shown measure 6.8 x 6.8 arcminutes and 3.5 x 3.9 arcminutes, respectively. North is up; East is left. Credit: ESO/I. Appenzeller, W. Seifert, O. Stahl, M. Zamani
The spiral galaxy NGC 925 reveals cosmic pyrotechnics in its spiral arms where bursts of star formation are taking place in the red, glowing clouds scattered throughout it. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgements: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
This is the first sunspot image taken on January 28, 2020 by the NSF’s Inouye Solar Telescope’s Wave Front Correction context viewer. The image reveals striking details of the sunspot’s structure as seen at the Sun’s surface. The sunspot is sculpted by a convergence of intense magnetic fields and hot gas boiling up from below. This image uses a warm palette of red and orange, but the context viewer took this sunspot image at the wavelength of 530 nanometers – in the greenish-yellow part of the visible spectrum. This is not the same naked eye sunspot group visible on the Sun in late November and early December 2020. Credit: NSO/NSF/AURA
Galaxy Galaxy, Burning Bright! / In the forests of the night lies a barred spiral galaxy called NGC 3583, imaged here by the NASA/ESA Hubble Space Telescope. This is a barred spiral galaxy with two arms that twist out into the Universe. This galaxy is located 98 million light-years away from the Milky Way. Two supernovae exploded in this galaxy, one in 1975 and another, more recently, in 2015. There are a few different ways that supernova can form. In the case of these two supernovae, the explosions evolved from two independent binary star systems in which the stellar remnant of a Sun-like star, known as a white dwarf, was collecting material from its companion star. Feeding off of its partner, the white dwarf gorged on the material until it reached a maximum mass. At this point, the star collapsed inward before exploding outward in a brilliant supernova. Two of these events were spotted in NGC 3583, and though not visible in this picture of the week, we can still marvel at the galaxy’s fearful symmetry. Credit: ESA/Hubble & NASA, A. Riess et al.
This color-composite shows a main part of the new Blanco DECam Bulge Survey of 250 million stars in our galaxy’s bulge. The 4 x 2 degrees excerpt can be explored in all its whopping 50,000 x 25,000 pixels in this zoomable version. In the image interstellar dust and gas seemingly acts like a red “filter” in front of the background stars, scattering the blue light away. Since we are surrounded by dust and gas in the Milky Way, this scattering effect is important to many parts of astronomy and is known as interstellar reddening. DECam was primarily funded by the U.S. Department of Energy. Credit: CTIO/NOIRLab/DOE/NSF/AURA Acknowledgment: Image processing: W. Clarkson (UM-Dearborn), C. Johnson (STScI), and M. Rich (UCLA), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.
One Amongst Millions / Looking deep into the Universe, the NASA/ESA Hubble Space Telescope catches a passing glimpse of the numerous arm-like structures that sweep around this barred spiral galaxy, known as NGC 2608. Appearing as a slightly stretched, smaller version of our Milky Way, the peppered blue and red spiral arms are anchored together by the prominent horizontal central bar of the galaxy. In Hubble photos, bright Milky Way stars will sometimes appear as pinpoints of light with prominent lens flares. A star with these features is seen in the lower right corner of the image, and another can be spotted just above the pale centre of the galaxy. The majority of the fainter points around NGC 2608, however, lack these features, and upon closer inspection they are revealed to be thousands of distant galaxies. NGC 2608 is just one among an uncountable number of kindred structures. Similar expanses of galaxies can be observed in other Hubble images such as the Hubble Deep Field which recorded over 3000 galaxies in one field of view. Credit: ESA/Hubble & NASA, A. Riess et al.
This striking image, streaked with bright swathes of color, captures the beautiful reflection nebula NGC 2170. The diffuse clouds of interstellar dust in the nebula scatter and reflect light from nearby stars, creating this vividly colorful scene. Dust grains reflect blue light from hot stars embedded in the nebula. And warm hydrogen gas glows a deep red. Seen as dark tendrils, dust also absorbs the light from stars and gas behind it. This particular nebula lies in the constellation Monoceros (The Unicorn) — a faint constellation on the celestial equator. It was observed using the SMARTS 0.9-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab. Credit: CTIO/NOIRLab/NSF/AURA Acknowledgments: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Elliptical galaxies are generally characterized by their relatively smooth appearance when compared with spiral galaxies (one of which is to the left), which have more flocculent structures interwoven with dust lanes and spiral arms. NGC 474 is at a distance of about 100 million light-years in the constellation of Pisces. This image shows unusual structures around NGC 474 characterized as tidal tails and shell-like structures made up of hundreds of millions of stars. These features are due to recent mergers (within the last billion years) or close interactions with smaller infalling dwarf galaxies. This image is an excerpt from the Dark Energy Survey, which has released a massive, public collection of astronomical data and calibrated images from six years of work. The Dark Energy Survey is a global collaboration that includes the Department of Energy's (DOE) Fermi National Accelerator Laboratory (Fermilab), the National Center for Supercomputing Applications (NCSA), and NSF’s NOIRLab. The image was taken with the Dark Energy Camera, fabricated by DOE, on the Víctor M. Blanco 4-meter Telescope. The quality of the survey can be appreciated by diving into the zoomable version of this wider excerpt showing a background tapestry of thousands of distant galaxies. Credit: DES/DOE/Fermilab/NCSA & CTIO/NOIRLab/NSF/AURA Acknowledgments: Image processing: DES, Jen Miller (Gemini Observatory/NSF's NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The blazing bright ball slicing through the center of this image is an example of a type of celestial body known as a centaur — a Solar System object that can be like both a comet and an asteroid. These fast moving icy objects reside in unstable orbits in the space between Jupiter and Neptune. The centaur in this image is named P/2019 LD2 (ATLAS), or LD2 for short. LD2 was observed from Gemini North, the Hawai‘i-based half of the international Gemini Observatory, which is a Program of NSF’s NOIRLab. LD2 is on the cusp of an important transition — it is the first centaur to be seen in the process of changing into a comet-like state. It is slowly being nudged closer and closer towards the inner Solar System, which is causing its tail to form, and it is on track to move within Jupiter’s orbit in 2063. Once it does, it will cease to be a centaur, and will become a Jupiter Family Comet instead — joining a population of comets orbiting the Sun in less than 20 years and roughly in the same plane as most of the rest of the Solar System. That astronomers are able to witness LD2’s transition is unique and it is particularly exciting as many astronomers will be able to observe this metamorphosis within their own lifetimes — a fascinating glimpse of astronomy in action. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Acknowledgments: PI: C.Schambeau (University of Central Florida) Image Processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Barnard’s Galaxy, a dwarf galaxy neighboring the Milky Way, is revealed in this stunning image from the Victor M. Blanco 4-m telescope at the Cerro Tololo Inter-American Observatory, operated by the NSF’s NOIRLab. The image reveals regions of intense star formation and a scattering of immense cosmic bubbles. Despite its small size, the galaxy contains some spellbinding cosmic objects. Glowing red regions of star formation are scattered throughout Barnard’s Galaxy, and indicate that incandescent star birth is widespread. Several other regions are well known in their own right, and have been well studied since they were first detected by Edwin Hubble in 1925. Credit: CTIO/NOIRLab/NSF/AURA Acknowledgments: P. Massey (Lowell Obs.), G. Jacoby, K. Olsen, C. Smith (NOAO/AURA/NSF) & T.A. Rector (NRAO/AUI/NSF). Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The international Gemini Observatory composite color image of the planetary nebula CVMP 1 imaged by the Gemini Multi-Object Spectrograph on the Gemini South telescope on Cerro Pachón in Chile. Credit: International Gemini Observatory/NOIRLab/NSF/AURA
The two galaxies in this image — NGC 672 (top right) and IC 1727 (bottom left) — appear to be so close that they are almost elbowing each other, like playful children. In fact, the galaxies shown in this beautifully detailed image taken at the Kitt Peak National Observatory, a program of NSF’s NOIRLab, are classified as a galactic pair, and the gravity of each galaxy influences the other. The pair are located around 20 million light-years away from Earth and the space between them spans over 80,000 light-years, a seemingly enormous gap. However, from the perspective of the galaxies’ themselves, that separation is not so significant, as it is roughly equivalent to the size of the galaxies themselves. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgements: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
A stunning long-exposure observation lasting 70 minutes from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, reveals the spiral galaxy NGC 1003 in glorious detail. NGC 1003 resides in front of a galaxy cluster — a vast collection of galaxies bound together by gravity. The long exposure time of this deep observation allowed these usually overlooked red background cluster galaxies to be captured. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgments: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Part of the SMASH dataset showing an unprecedented wide-angle view of the Large Magellanic Cloud. The Large and Small Magellanic Clouds are the largest satellite galaxies of the Milky Way and, unlike the rest of the satellite galaxies, are still actively forming stars — and at a rapid pace. The depth of these survey data can be appreciated by the number of stars visible in the outer regions of the galaxy, as seen in the lower part of the image. Credit: CTIO/NOIRLab/NSF/AURA/SMASH/D. Nidever (Montana State University) Acknowledgment: Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Six circumstellar disks selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). These images highlight the diversity of shapes and sizes that these disks can take and show the outer reaches of star systems in their formative years. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The spiral galaxy NGC 2541 is shown in extravagant detail in this astronomical snapshot from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. Astronomers recognize a variety of galaxy types, and NGC 2541 is classified as an unbarred spiral galaxy. These galaxies possess spectacular spiral arms like the ones shown here, but lack the central bar-shaped structure displayed by galaxies such as the Milky Way. NGC 2541 lies 37 million light-years from Earth in the constellation of Lynx (The Lynx). Sandwiched between the constellations of Ursa Major, Gemini, and Leo, Lynx is one of 10 new constellations established by the 17th century astronomer Johannes Hevelius. The constellation is composed of very faint stars, leading Hevelius to claim that only the lynx-eyed — people with exceptionally keen eyesight — would be able to spot this unobtrusive constellation. Credit: KPNO/NOIRLab/NSF/AURA Acknowledgements: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Excerpt of main image without lensing map Excerpt of main image without lensing map LoVoCCS takes advantage of an astrophysical phenomenon called weak gravitational lensing to measure the mass and matter distributions of these clusters. Credit: CTIO/NOIRLab/NSF/AURA
The remarkably thin galaxy IC 2233 is featured in this image from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. IC 2233’s needle-thin profile is due to both its structure and its orientation towards Earth. The galaxy’s orientation — known to astronomers as inclination — is almost exactly side-on, making this one of the flattest galaxies known. The exposure of this particular image is deep and the entire field littered with galaxies of various types of inclinations. As well as lying flat from our point of view, IC 2233 also lacks the prominent bulge that fattens the profile of spiral galaxies such as Andromeda and the Milky Way. The wafer-thin profile of this celestial needle has been fascinating observers for nearly 150 years — IC 2233 was first discovered in 1874 by the Welsh amateur astronomer Isaac Roberts, one of the pioneers of astrophotography. Credit: KPNO/NOIRLab/NSF/AURA. Acknowledgments: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Using the Dark Energy Camera at Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab, astronomers are measuring weak gravitational lensing to map the distribution of mass in nearby galaxy clusters. As well as producing remarkable images like this one, the information will shed light on the relationships between the constituent parts of nearby galaxy clusters, such as gas, stellar populations, and dark matter. The galaxy cluster Abell 3827 is the subject of this striking image. In addition to featuring a field of galaxies and foreground stars, the image is overlaid with a map with hues of red, blue and purple. Though they are attractive, these colors aren’t for decoration — they represent the distribution of mass in the heart of Abell 3827 with red showing the largest mass concentration. Credit: CTIO/NOIRLab/NSF/AURA
Pictured here is part of the captivating galaxy NGC 2525. Located nearly 70 million light-years from Earth, this galaxy is part of the constellation of Puppis in the southern hemisphere. Together with the Carina and the Vela constellations, it makes up an image of the Argo from ancient greek mythology. On the left, a brilliant supernova is clearly visible in the image. The supernova is formally known as SN2018gv and was first spotted in mid-January 2018. The NASA/ESA Hubble Space Telescope captured the supernova in NGC 2525 as part of one of its major investigations; measuring the expansion rate of the Universe, which can help answer fundamental questions about our Universe’s very nature. Supernovae like this one can be used as cosmic tape measures, allowing astronomers to calculate the distance to their galaxies. ESA/Hubble has now published a unique time-lapse of this galaxy and it’s fading supernova. Credit: ESA/Hubble & NASA, A. Riess and the SH0ES team Acknowledgment: Mahdi Zamani
The southern plane of the Milky Way from the ATLASGAL survey (annotated) A spectacular new image of the Milky Way has been released to mark the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The APEX telescope in Chile has mapped the full area of the Galactic Plane visible from the southern hemisphere at submillimetre wavelengths — between infrared light and radio waves. The new finely detailed images complement those from recent space-based surveys. The pioneering 12-metre APEX telescope allows astronomers to study the cold Universe: gas and dust only a few tens of degrees above absolute zero. The APEX data, at a wavelength of 0.87 millimetres, shows up in red and the background blue image was imaged at shorter infrared wavelengths by the NASA Spitzer Space Telescope as part of the GLIMPSE survey. The fainter extended red structures come from complementary observations made by ESA's Planck satellite. Many of the most prominent objects are named and the parts of the galaxy that are shown in the three slices are indicated at the right. Credit: ESO/APEX/ATLASGAL consortium/NASA/GLIMPSE consortium/ESA/Planck
The afterglow of GRB181123B, captured by the Gemini North telescope. The afterglow position is marked by a circle. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/K. Paterson & W. Fong (Northwestern University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
NOIRLab’s International Gemini Observatory continues tracking a visiting comet from beyond our Solar System. Gemini’s second image release of the comet, discovered by Russian amateur astronomer Gennady Borisov in August of this year, reveals the evolution of the comet as it approaches its closest approach to our sun in December. The image also features the distant background galaxy (going by the catchy designation: 2dFGRS TGN363Z174) that happened to appear adjacent to the comet when the image was captured on the night of November 11–12 2019. “The comet is doing what we would expect a comet to do as it approaches the Sun,” according to Meg Schwamb of Queen’s University Belfast who led the observations. “Gas is being vaporized and the gas cloud, or coma, is expanding and being blown away from the Sun. It’s reassuring that comets from beyond our Solar System behave as we would expect!” Schwamb’s team obtained the image as part of a Fast Turnaround program using the Gemini North telescope and a brand new rapid data reduction pipeline called Dragons. “Dragons allowed us to reduce these data in less than 24 hours which is critical when tracking something which evolves as quickly as a comet,” said Rosemary Pike who is a member of the team from Taiwan’s Academia Sinica Institute of Astronomy and Astrophysics. The data are part of a long-term program to observe the visiting comet and understand how this visitor from beyond our Solar System might differ from comets originating within our own planetary system. A previous image of the comet, obtained with the Gemini North telescope was released on September 13th and was one of the first images released of the comet. The previous image is available here. Credit: International Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory/AURA
Gemini Observatory Captures Multicolor Image of First-ever Interstellar Comet. Credit: Gemini Observatory/NSF/AURA
The Orion Nebula and cluster from the VLT Survey Telescope OmegaCAM — the wide-field optical camera on ESO’s VLT Survey Telescope (VST) — has captured the spectacular Orion Nebula and its associated cluster of young stars in great detail, producing this beautiful new image. This famous object, the birthplace of many massive stars, is one of the closest stellar nurseries, at a distance of about 1350 light-years. Credit: ESO/G. Beccari
One Large Stellar Latte To Go / Far away in the Ursa Major constellation is a swirling galaxy that would not look out of place on a coffee made by a starry-eyed barista. NGC 3895 is a barred spiral galaxy that was first spotted by William Herschel in 1790 and was later observed by the NASA/ESA Hubble Space Telescope. Hubble's orbit high above the Earth's distorting atmosphere allows astronomers to make the very high resolution observations that are essential to opening new windows on planets, stars and galaxies — such as this beautiful view of NGC 3895. The telescope is positioned approximately 570 km above the ground, where it whirls around Earth at 28 000 kilometres per hour and takes 96 minutes to complete one orbit. Credit: ESA/Hubble, NASA, and R. Barrows
Comparison of the central part of the Milky Way at different wavelengths (annotated) This comparison shows the central regions of the Milky Way observed at different wavelengths. The top panel shows compact sources of submillimetre radiation detected by APEX as part of the ATLASGAL survey, combined with complementary data from ESA’s Planck satellite, to capture more extended features. The second panel shows the same region as seen in shorter, infrared, wavelengths by the NASA Spitzer Space Telescope. The third panel shows the same part of sky again at even shorter wavelengths, the near-infrared, as seen by ESO’s VISTA infrared survey telescope at the Paranal Observatory in Chile. Regions appearing as dark dust tendrils here show up brightly in the ATLASGAL view. Finally the bottom picture shows the more familiar view in visible light, where most of the more distant structures are hidden from view. The significance of the colours varies from image to image and they cannot be directly compared. Credit: ESO/ATLASGAL consortium/NASA/GLIMPSE consortium/VVV Survey/ESA/Planck/D. Minniti/S. Guisard Acknowledgement: Ignacio Toledo, Martin Kornmesser
The enigmatic CK Vulpeculae nebula. The team of astronomers measured the speeds and changes in positions of the two small reddish arcs about 1/4 of the way up from the bottom and 1/4 of the way down from the top to help determine that the nebula is expanding five times faster than previously thought. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
VISTA’s view of the Small Magellanic Cloud The Small Magellanic Cloud (SMC) galaxy is a striking feature of the southern sky even to the unaided eye. But visible-light telescopes cannot get a really clear view of what is in the galaxy because of obscuring clouds of interstellar dust. VISTA’s infrared capabilities have now allowed astronomers to see the myriad of stars in this neighbouring galaxy much more clearly than ever before. The result is this record-breaking image — the biggest infrared image ever taken of the Small Magellanic Cloud — with the whole frame filled with millions of stars. As well as the SMC itself this very wide-field image reveals many background galaxies and several star clusters, including the very bright 47 Tucanae globular cluster at the right of the picture. Credit: ESO/VISTA VMC
Part of the SMASH dataset showing what is arguably the best wide-angle view of the Small Magellanic Cloud to date. The Large and Small Magellanic Clouds are the largest satellite galaxies of the Milky Way and, unlike the rest of the satellite galaxies, are still actively forming stars — and at a rapid pace. Credit: CTIO/NOIRLab/NSF/AURA/SMASH/D. Nidever (Montana State University) Acknowledgment: Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
Hubble Space Telescope image of SN 2019ehk (annotated) Hubble Space Telescope image of SN 2019ehk in its spiral host galaxy, Messier 100. The image is a composite made of pre- and post-explosion images. Credit: CTIO/SOAR/NOIRLab/NSF/AURA/Northwestern University/C. Kilpatrick/University of California Santa Cruz/NASA-ESA Hubble Space Telescope
A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo. Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies. The final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. Credit: DESI Legacy Imaging Surveys/LBNL/DOE & KPNO/CTIO/NOIRLab/NSF/AURA
The southern plane of the Milky Way from the ATLASGAL survey This image of the Milky Way has been released to mark the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The APEX telescope in Chile has mapped the full area of the Galactic Plane visible from the southern hemisphere for the first time at submillimetre wavelengths — between infrared light and radio waves — and in finer detail than recent space-based surveys. The APEX data, at a wavelength of 0.87 millimetres, shows up in red and the background blue image was imaged at shorter infrared wavelengths by the NASA Spitzer Space Telescope as part of the GLIMPSE survey. The fainter extended red structures come from complementary observations made by ESA's Planck satellite. Note that the far right section of this long and thin image does not include Planck imaging. To fully appreciate this image click on it and zoom and scroll sideways. Credit: ESO/APEX/ATLASGAL consortium/NASA/GLIMPSE consortium/ESA/Planck
The planetary nebula IC 4406 seen with MUSE and the AOF The coupling of the AOF with MUSE gives access to both greater sharpness and a wide dynamic range when observing celestial objects like planetary nebulae. These new observations of IC 4406 revealed shells that have never been seen before, along with the already familiar dark dust structures in the nebula that gave it the popular name the Retina Nebula. This image shows a small fraction of the total data collected by the MUSE using the AOF system and demonstrates the increased abilities of the new AOF equipped MUSE instrument. Credit: ESO/J. Richard (CRAL)
xamples of gravitational lenses found in the DESI Legacy Survey data. Credit: DESI Legacy Imaging Surveys/LBNL/DOE & KPNO/CTIO/NOIRLab/NSF/AURA
The planetary nebula NGC 6563 observed with the AOF The Adaptive Optics Facility works to remove the blurring effect of Earth’s atmosphere. When used one can see much finer details in the faint planetary nebula NGC 6563 as compared to the natural sky quality. Credit: ESO/P. Weilbacher (AIP)
NGC 6369 Known as the Little Ghost Nebula, NGC 6369 is a planetary nebula in the constellation Ophiuchus, the serpent-bearer. The nebula is relatively faint with an apparent magnitude of 12.9 and the clear detail of this image shows the power of the AOF-equipped MUSE instrument of the VLT. The white dwarf star is clearly visible in the middle of the nebular gas, which is expanding out in rings. Credit: ESO/P. Weilbacher (AIP)
VLT/MUSE image of the galaxy NGC 4993 and associated kilonova This image from the MUSE instrument on ESO’s Very Large Telescope at the Paranal Observatory in Chile shows the galaxy NGC 4993, about 130 million light-years from Earth. The galaxy is not itself unusual, but it contains something never before witnessed, the aftermath of the explosion of a pair of merging neutron stars, a rare event called a kilonova (seen just above and slightly to the left of the centre of the galaxy). This merger also produced gravitational waves and gamma rays, both of which were detected by LIGO-Virgo and Fermi/INTEGRAL respectively. By also creating a spectrum for each part of the object MUSE allows the emission from glowing gas to be seen, which appears in red here and reveals a surprising spiral structure. Credit: ESO/J.D. Lyman, A.J. Levan, N.R. Tanvir
Starbursts and slow burns This is one of 74 nearby galaxies whose stellar nurseries were recently observed by the Atacama Large Millimeter/submillimeter Array, or ALMA, in an astronomical census called Physics at High Angular resolution in Nearby GalaxieS (PHANGS). So far, around 100 000 of these stellar nurseries have been imaged in over 750 hours of observation. ALMA’s remarkable sensitivity provides data at high enough resolution to study these regions in detail, and shows that some are bursting with new stars, while others evolve more gradually. This anticipated diversity in the process of how stars form was the motivation behind this enormous effort. There have long been theories that aimed to explain how and why these differences might occur, some involving the characteristics of the home galaxy itself — properties such as size, age, and internal dynamics — but our lack of high-resolution data had been an obstacle to testing them. The vast quantity and variety of data yielded by PHANGS are already helping astronomers to understand more, even though the census is only a third complete. The project aims to observe a total of about 300 000 stellar nurseries and by the end it should significantly advance our understanding of how a galaxy’s properties influence the way in which it forms new stars. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton
Stunning Exoplanet Time-lapse ESO's Very Large Telescope (VLT) has captured an unprecedented series of images showing the passage of the exoplanet Beta Pictoris b around its parent star. This young massive exoplanet was initially discovered in 2008 using the NACO instrument at the VLT. The same science team since tracked the exoplanet from late 2014 until late 2016, using the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) — another instrument on the VLT. Beta Pictoris b then passed so close to the halo of the star that no instrument could resolve them from one another. Almost two years later, after seeming to merge into the image of the star, Beta Pictoris b has now emerged from the halo. This reappearance was captured again by SPHERE. The complete series of images, with the bright glow of the star Beta Pictoris blocked out, have been compiled to create a stunning and unique time-lapse of the long-period orbit of Beta Pictoris b. SPHERE caught sight of Beta Pictoris b by looking at it directly — not by inferring its existence. Most known exoplanets have been discovered using indirect methods — observing how they affect a star's position or brightness. ESO's SPHERE specialises in a method called direct imaging, hunting for exoplanets by taking their photographs. This extraordinarily challenging endeavour provides us with clear images of distant worlds such as Beta Pictoris b, 63 light-years away. Beta Pictoris b orbits its star at a distance similar to that between the Sun and Saturn, approximately 1.3 billion kilometres, meaning it’s the most closely orbiting exoplanet ever to have been directly imaged. The surface of this young planet is still hot, around 1 500 °C, and the light it emits enabled SPHERE to discover it and track its orbit, seeing it emerge from its passage in front of its parent star. Whilst a glance at these images might suggest that the planet transits the star, eclipsing a little of its light, Beta Pictoris b does not in fact quite transit. These images are a remarkable achievement, heralding a new era in one of the most exciting and challenging areas of astronomy — discovering and characterising exoplanets. Credit: ESO/Lagrange/SPHERE consortium.
Star formation region Lupus 3 A dark cloud of cosmic dust snakes across this spectacular wide field image, illuminated by the brilliant light of new stars. This dense cloud is a star-forming region called Lupus 3, where dazzlingly hot stars are born from collapsing masses of gas and dust. This image was created from images taken using the VLT Survey Telescope and the MPG/ESO 2.2-metre telescope and is the most detailed image taken so far of this region. Credit: ESO/R. Colombari
A portrait of a beauty Nuzzled in the chest of the constellation Virgo (the Virgin) lies a beautiful cosmic gem — the galaxy Messier 61. This glittering spiral galaxy is aligned face-on towards Earth, thus presenting us with a breathtaking view of its structure. The gas and dust of the intricate spiral arms are studded with billions of stars. This galaxy is a bustling hub of activity with a rapid rate of star formation, and both a massive nuclear star cluster and a supermassive black hole buried at its heart. Messier 61 is one of the largest members of the Virgo Cluster, which is made up of more than a thousand galaxies, and is itself at the centre of the Virgo Supercluster — to which our Milky Way also belongs. This dazzling beauty was first discovered in 1779, and it has been capturing astronomers’ interest ever since. Set against a dark sky littered with galaxies, this image shows the awe-inspiring M61 in its full glory — even at its distance of over 50 million light-years. This image was taken as part of ESO’s Cosmic Gems Programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. In case the data collected could be useful for future scientific purposes, these observations are saved and made available to astronomers through ESO’s Science Archive. Credit: ESO
Star forming gas clouds in NGC 6822 This image is a composite of older observations made with the Wide Field Imager attached to the 2.2-metre MPG/ESO telescope at ESO’s La Silla Observatory and new data collected by the Atacama Large Millimeter/submillimeter Array (ALMA). The observations by ALMA reveal the structure of star-forming gas clouds in unprecedented resolution. Credit: ESO, ALMA (ESO/NAOJ/NRAO)/A. Schruba, VLA (NRAO)/Y. Bagetakos/Little THINGS
SPHERE image of the newborn planet PDS 70b SPHERE image of the newborn planet PDS 70b This spectacular image from the SPHERE instrument on ESO's Very Large Telescope is the first clear image of a planet caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the centre of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star. Credit: ESO/A. Müller et al.
Coils of Apep The VISIR instrument on ESO’s VLT captured this stunning image of a newly-discovered massive binary star system. Nicknamed Apep after an ancient Egyptian deity, it could be the first gamma-ray burst progenitor to be found in our galaxy. Apep’s stellar winds have created the dust cloud surrounding the system, which consists of a binary star with a fainter companion. With 2 Wolf-Rayet stars orbiting each other in the binary, the serpentine swirls surrounding Apep are formed by the collision of two sets of powerful stellar winds, which create the spectacular dust plumes seen in the image. The reddish pinwheel in this image is data from the VISIR instrument on ESO’s Very Large Telescope (VLT), and shows the spectacular plumes of dust surrounding Apep. The blue sources at the centre of the image are a triple star system — which consists of a binary star system and a companion single star bound together by gravity. Though only two star-like objects are visible in the image, the lower source is in fact an unresolved binary Wolf-Rayet star. The triple star system was captured by the NACOadaptive optics instrument on the VLT. Credit: ESO/Callingham et al.
In space, being outshone is an occupational hazard. This NASA/ESA Hubble Space Telescope image captures a galaxy named NGC 7250. Despite being remarkable in its own right — it has bright bursts of star formation and recorded supernova explosions — it blends into the background somewhat thanks to the gloriously bright star hogging the limelight next to it. This bright object is a single and little-studied star named TYC 3203-450-1, located in the constellation of Lacerta (The Lizard), much closer than the much more distant galaxy. Only this way a normal star can outshine an entire galaxy, consisting of billions of stars. Astronomers studying distant objects call these stars “foreground stars” and they are often not very happy about them, as their bright light is contaminating the faint light from the more distant and interesting objects they actually want to study. In this case TYC 3203-450-1 million times closer than NGC 7250 which lies over 45 million light-years away from us. Would the star be the same distance as NGC 7250, it would hardly be visible in this image. Credit: ESA/Hubble & NASA
Celestial spiral with a twist Although it looks like the pattern of a shell on the beach, this intriguing spiral is in fact astronomical in nature. The Atacama Large Millimeter/submillimeter Array (ALMA) captured this remarkable image of a binary star system, where two stars — LL Pegasi and its companion — are locked in a stellar waltz, orbiting around their common centre of gravity. The old star LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula, and the distinct spiral shape is the imprint made by the stars orbiting in this gas. The spiral spans light-years and winds around with extraordinary regularity. Based on the expansion rate of the spiralling gas, astronomers estimate that a new “layer” appears every 800 years — approximately the same time it takes for the two stars to complete one orbit around each other. LL Pegasi was first highlighted about 10 years ago when the NASA/ESA Hubble Space Telescope obtained a picture of the almost-perfect spiral structure. This was the first time a spiral pattern had been found in material surrounding an old star. Now, ALMA’s observations, of which this image only shows one “cross-section”, have added an extra dimension to reveal the exquisitely-ordered 3D geometry of the spiral pattern. A full view of the 3D video can be seen in this video. Credit: ALMA (ESO/NAOJ/NRAO)/H. Kim et al.
Through the Hourglass This object is possibly the oldest of its kind ever catalogued: the hourglass-shaped remnant named CK Vulpeculae. Originally thought to be a nova, classifying this unusually shaped object correctly has proven challenging over the years. A number of possible explanations for its origins have been considered and discarded. It is now thought to be the result of two stars colliding — although there is still debate about what type of stars they were. CK Vulpeculae was first spotted on 20 June 1670 by French monk and astronomer Père Dom Anthelme. When it first appeared it was easily visible with the naked eye; over the subsequent two years the flare varied in brightness and disappeared and reappeared twice, before finally vanishing from view for good. During the twentieth century, astronomers came to understand that most novae could be explained by the runaway explosive behaviour and interactions between two close stars in a binary system. The features seen around CK Vulpeculae didn’t seem to fit this model particularly well,however, puzzling astronomers for many years. The central part of the remnant has now been studied in detail using the Atacama Large Millimeter/submillimeter Array (ALMA). This striking image shows the best view of the object to date, and traces the cosmic dust and emission within and around CK Vulpeculae to reveal its intricate structure. CK Vulpeculae harbours a warped dusty disc at its centre and gaseous jets which indicate some central system propelling material outwards. These new observations are the first to bring this system into focus, suggesting a solution to a 348 year-old mystery. Credit: ALMA (ESO/NAOJ/NRAO)/S. P. S. Eyres
Hidden from view This ESO Picture of the Week shows the centre of a galaxy named NGC 5643. This galaxy is located 55 million light-years from Earth in the constellation of Lupus (The Wolf), and is known as a Seyfert galaxy. Seyfert galaxies have very luminous centres — thought to be powered by material being accreted onto a supermassive black hole lurking within — that can also be shrouded and obscured by clouds of dust and intergalactic material. As a result, it can be difficult to observe the active centre of a Seyfert galaxy. NGC 5643 poses a further challenge; it is viewed at a high inclination, making it even trickier to view its inner workings. However, scientists have used the Atacama Large Millimeter/submillimeter Array (ALMA) together with archival data from the Multi Unit Spectroscopic Explorer (MUSE) instrument on ESO’s Very Large Telescope to reveal this view of NGC 5643 — complete with energetic outflowing ionised gas pouring out into space. These impressive outflows stretch out on either side of the galaxy, and are caused by matter being ejected from the accretion disc of the supermassive black hole at NGC 5643’s core. Combined, the ALMA and VLT data show the galaxy’s central region to have two distinct components: a spiraling, rotating disc (visible in red) consisting of cold molecular gas traced by carbon monoxide, and the outflowing gas, traced by ionised oxygen and hydrogen (in blue-orange hues) perpendicular to the inner nuclear disc. Credit: ESO/A. Alonso-Herrero et al.; ALMA (ESO/NAOJ/NRAO)
A Cosmic Bat in Flight Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula. Too dim to be discerned by the naked eye, NGC 1788 reveals its soft colours to ESO's Very Large Telescope in this image — the most detailed to date. Credit: ESO
Caught “Pink-Handed” The Milky Way contains many regions of starbirth — areas where new stars are springing to life within collapsing clumps of gas and dust. One such region, named Gum 26, is shown here as imaged by the FORS instrument on ESO’s Very Large Telescope in Chile. Gum 26 is located roughly 20,000 light-years away in the southern constellation of Vela (The Sails). It is something known as an HII region or emission nebula, where the intense ultraviolet radiation streaming from newly-formed stars ionises the surrounding hydrogen gas, causing it to emit a faint pinkish glow. By catching new stars “pink-handed” in this manner, astronomers can learn more about the conditions under which stars arise, and study how they influence their cosmic environment. This image was created as part of the ESO Cosmic Gems programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive. Credit: ESO
Highest resolution image of the 1919 solar eclipse Almost exactly 100 years ago, a remarkable event occurred: a total solar eclipse. This eclipse was special in more ways than one. Firstly, at just under seven minutes in duration, it was the longest such eclipse in over 500 years. Secondly, it was used by astronomers to explore the then-new theory of general relativity — with successful and groundbreaking results. Einstein published his general theory of relativity in 1915. The total solar eclipse of 1919 offered the perfect opportunity to test it experimentally, by exploring whether — and how — the immense gravity of the Sun bends and distorts incoming light from more distant stars, as predicted by Einstein’s theory. For a brief moment during the eclipse, the Moon would block the Sun’s light in the sky and make visible some of the stars that lie close to the line of sight of the Sun, not normally visible during the daytime. By measuring the positions of these stars during the eclipse and comparing them to their positions at night, when the sun is not in the field of view, it would be possible to determine whether their light rays bends while passing close to the Sun. Three astronomers — Arthur Eddington, Frank Watson Dyson, and Andrew Crommelin — played key roles in this 1919 experiment. Eddington and Crommelin travelled to locations at which the eclipse would be total — Eddington to the West African island of Príncipe, Crommelin to the Brazilian town of Sobral — while Dyson coordinated the attempt from England. Eddington and Crommelin imaged the eclipse using the technology of the time: photographic plates made of glass. Sadly, the original plates from the 1919 expedition (one of which was reproduced in Dyson’s original paper) have been lost — but, luckily, copies of one of the plates were made and sent to observatories around the world to allow scientists everywhere to see the evidence in support of relativity with their own eyes. One copy of a plate from Sobral went to Landessternwarte Heidelberg-Königstuhl, who recently scanned theirs as part of the Heidelberg Digitized Astronomical Plates (HDAP) project . The image shown here is arguably the highest resolution image of the 1919 eclipse, and is the result of applying modern image processing techniques — including image restoration, noise reduction, and removal of artifacts — to that plate copy (un-annotated version here). It unveils stunning details in the solar corona, a giant prominence emerging from the upper right part of the Sun, and stars in the constellation of Taurus (The Bull) that were used to confirm general relativity’s predictions . Notes  HDAP receives funding under grant No. 00.071.2005 of the Klaus Tschira Foundation. The original high-resolution scan before the digital restoration is provided here for historical purposes.  Dyson’s original paper concludes with the paradigm-changing graph on p.332 plotting the displacements of the stars during the eclipse against their distance from the solar disc’s centre. This shows a clear relation (solid line) — the stars closer to the solar disc are deflected more than those further away, and by roughly the amount predicted by general relativity (twice that predicted by Newtonian theory, which is represented by the dotted line). Credit: ESO/Landessternwarte Heidelberg-Königstuhl/F. W. Dyson, A. S. Eddington, & C. Davidson
ALMA Reveals Inner Web of Stellar Nursery This spectacular and unusual image shows part of the famous Orion Nebula, a star formation region lying about 1350 light-years from Earth. It combines a mosaic of millimetre wavelength images from the Atacama Large Millimeter/submillimeter Array (ALMA) and the IRAM 30-metre telescope, shown in red, with a more familiar infrared view from the HAWK-I instrument on ESO’s Very Large Telescope, shown in blue. The group of bright blue-white stars at the left is the Trapezium Cluster — made up of hot young stars that are only a few million years old. Credit: ESO/H. Drass/ALMA (ESO/NAOJ/NRAO)/A. Hacar
Caption: The Daniel K. Inouye Solar Telescope has produced the highest resolution image of the Sun’s surface ever taken. In this picture taken at 789nm, we can see features as small as 30km (18 miles) in size for the first time ever. The image shows a pattern of turbulent, “boiling” gas that covers the entire sun. The cell-like structures – each about the size of Texas – are the signature of violent motions that transport heat from the inside of the sun to its surface. Hot solar material (plasma) rises in the bright centers of “cells,” cools off and then sinks below the surface in dark lanes in a process known as convection. In these dark lanes we can also see the tiny, bright markers of magnetic fields. Never before seen to this clarity, these bright specks are thought to channel energy up into the outer layers of the solar atmosphere called the corona. These bright spots may be at the core of why the solar corona is more than a million degrees! This image covers an area 36,500 × 36,500 km (22,600 × 22,600 miles or 51 × 51 arcseconds). Credit: NSO/AURA/NSF
The Whirlpool Galaxy (M51a) with it's sparkling arms is the first galaxy found to have a spiral structure. The Whirlpool Galaxy (M51a) with it's sparkling arms is the first galaxy found to have a spiral structure. Credit: ESA/Hubble and Digitized Sky Survey 2. Acknowledgements: Mahdi Zamani (ESA/Hubble)
Starlink Satellites Imaged from CTIO Earlier this week, while observing with DECam on the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF's NOIRLab, astronomers Clara Martínez-Vázquez and Cliff Johnson noticed something interesting. One of their images, the 333 seconds-exposure seen here, contained at least 19 streaks that they quickly surmised were due to the second batch of Starlink satellites launched last week. The gaps in the satellite tracks are due to the gaps between the DECam CCD chips in the 2.2-degree field. At the same time, the CTIO all-sky camera recorded the satellites which were even visible with the unaided eye. Several frames from that camera can be seen in this timelapse video from CTIO. Gemini North Cloud Camera timelapse video of the passage of the Starlink satellite cluster over Maunakea. This sequence was obtained on the night of 12-13 November. Credit: CTIO/NOIRLab/NSF/AURA/DECam DELVE Survey
Location of K2-25 A diagram showing the location of exoplanet K2-25b’s host star in the Hyades star cluster. Credit: NOIRLab/NSF/AURA/Digitized Sky Survey 2
Hubble Space Telescope image of SN 2019ehk Hubble Space Telescope image of SN 2019ehk in its spiral host galaxy, Messier 100. The image is a composite made of pre- and post-explosion images. Credit: CTIO/SOAR/NOIRLab/NSF/AURA/Northwestern University/C. Kilpatrick/University of California Santa Cruz/NASA-ESA Hubble Space Telescope
Comet NEOWISE Rotation Sequence (Images) Images of Comet NEOWISE obtained with Gemini North on Hawai‘i’s Maunakea on the night of 1 August 2020. This sequence was obtained using the Gemini Multi-Object Spectrograph (GMOS) with the 468/8 nm filter and digitally enhanced using a dedicated algorithm. The field of view is 2 arcminutes across. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Drahus/P. Guzik
A Universe Aglow Deep observations made with the MUSE spectrograph on ESO’s Very Large Telescope have uncovered vast cosmic reservoirs of atomic hydrogen surrounding distant galaxies. The exquisite sensitivity of MUSE allowed for direct observations of dim clouds of hydrogen glowing with Lyman-alpha emission in the early Universe — revealing that almost the whole night sky is invisibly aglow. Credit: ESA/Hubble & NASA, ESO/ Lutz Wisotzki et al.
Fast Radio Burst 180916 Host Galaxy (annotated) Image of the host galaxy of FRB 180916 (center) acquired with the 8-meter Gemini-North telescope of NOIRLab on Hawaii’s Maunakea. Images acquired in SDSS g’, r’, and z’ filters are used for the blue, green, and red colors, respectively. The position of the FRB in the spiral arm of the galaxy is marked by a green circle. Credit: Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory/AURA
NEID First Light Spectrum (annotated) First light spectrum of 51 Pegasi as captured by NEID on the WIYN telescope with blowup of a small section of the spectrum. The right panel shows the light from the star, highly dispersed by NEID, from short wavelengths (bluer colors) to long wavelengths (redder colors). The colors shown, which approximate the true color of the starlight at each part of image, are included for illustrative purposes only. The region in the small white box in the right panel, when expanded (left panel), shows the spectrum of the star (longer dashed lines) and the light from the wavelength calibration source (dots). Deficits of light (dark interruptions) in the stellar spectrum, are due to stellar absorption lines — “fingerprints” of the elements that are present in the atmosphere of the star. By measuring the subtle motion of these features, to bluer or redder wavelengths, astronomers can detect the “wobble” of the star produced in response to its orbiting planet. Credit: Guðmundur Kári Stefánsson/Princeton University/Penn State/NSF’s National Optical-Infrared Astronomy Research Laboratory/KPNO/AURA
Minimoon 2020 CD3 in Color International Gemini Observatory image of 2020 CD3 (center, point source) obtained with the 8-meter Gemini North telescope on Hawaii’s Maunakea. The image combines three images each obtained using different filters to produce this color composite. 2020 CD3 remains stationary in the image since it was being tracked by the telescope as it appears to move relative to the background stars, which appear trailed due to the object’s motion. Credit: The international Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory/AURA/G. Fedorets
SPHERE images a zoo of dusty discs around young stars New images from the SPHERE instrument on ESO’s Very Large Telescope are revealing the dusty discs surrounding nearby young stars in greater detail than previously achieved. They show a bizarre variety of shapes, sizes and structures, including the likely effects of planets still in the process of forming. Credit: ESO/H. Avenhaus et al./E. Sissa et al./DARTT-S and SHINE collaborations
The Pirate of the Southern Skies This vivid picture of an active star forming region — NGC 2467, otherwise known as the Skull and Crossbones nebula — is as sinister as it is beautiful. This image of dust, gas and bright young stars, gravitationally bound into the form of a grinning skull, was captured with the FORS instrument on ESO’s Very Large Telescope (VLT). Whilst ESO’s telescopes are usually used for the collection of science data, their immense resolving power makes them ideal for capturing images such as this — which are beautiful for their own sake. Credit: ESO
Galaxies that appear in the full field of Image of the Week iotw2053. The individual images are here. Credit: KPNO/NOIRLab/NSF/AURA. Acknowledgments: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
These images of Jupiter were taken in infrared light using the international Gemini Observatory, a program of NSF’s NOIRLab on 8 April 2019. Because the telescope must observe through the Earth’s atmosphere, any disturbances in the air such as wind or temperature changes will distort and blur the image (left). This greatly limits the resolution the telescope can achieve on a target when only one image is taken. However, during a single night of “lucky imaging” observations, the telescope takes hundreds of exposures of the target. Some will be blurred, but many exposures will be taken when the view to space is still and clear of disturbances (right). In these “lucky” images, much smaller, more complex details on Jupiter are revealed. The research team finds the sharpest of these exposures, and compiles them into a mosaic of the whole disk. Credit: International Gemini Observatory/NOIRLab/NSF/AURA M.H. Wong (UC Berkeley) and team Acknowledgments: Mahdi Zamani
The Birth of the Hunter The constellation of Orion (The Hunter) is one of the most recognisable collections of stars in the night sky. We have noted Orion’s prominent stars for tens of thousands of years at least, and likely far longer. Chinese astronomers called it 参宿 or Shēn, literally “three stars”, for its three bright dots (which form the Hunter’s belt). The ancient Egyptians regarded it as the gods Sah and Sopdet, manifestations of Osiris and Isis, respectively, whereas Greek astronomers saw a brave hunter — the eponymous Orion — with his sword above his head, ready to strike. Mythology aside, Orion is a fascinating patch of sky. This image, from ESO's Very Large Telescope, shows a reflection nebula nestled at the heart of the constellation — NGC 2023. Located close to the well-known Horsehead and Flame Nebulae, NGC 2023 lurks about 1500 light-years away from Earth, and is one of the largest reflection nebulae in the sky. Reflection nebulae are clouds of interstellar dust that reflect the light from nearby or internal sources, like fog around a car headlight. NGC 2023 is illuminated by a massive young star named HD 37903. The star is extremely hot — several times hotter than the Sun — and its bright blue-white light causes NGC 2023’s milky glow. Such nebulae are often the birthplaces of stars, and contain a clumpy distribution of gas that’s significantly denser than the surrounding medium. Under the influence of gravity, these clumps attract one another and merge, eventually creating a new star. In a few million years time, Orion's Belt may gain a new star! The image was taken with the VLT’s FORS (FOcal Reducer and Spectrograph) instrument as part of the ESO Cosmic Gems programme. This initiative produces images of interesting and visually attractive objects using ESO telescopes, for the purposes of education and outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive. Credit: ESO
Small Part of DECam image of the bulge of the Milky Way. Credit: CTIO/NOIRLab/DOE/NSF/AURA Acknowledgment: Image processing: W. Clarkson (UM-Dearborn), C. Johnson (STScI), and M. Rich (UCLA), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.
Shaking stars On the night of 20 January 2019 Coquimbo, Chile shook with the force of a magnitude 6.7 earthquake. Although Coquimbo lies 90 kilometres from ESO’s La Silla Observatory, its effects were far from unnoticed. This unique image shows the earthquake as recorded by the Rapid Action Telescope for Transient Objects (TAROT), a telescope designed to monitor gamma-ray bursts. On the night in question, TAROT was imaging geostationary satellites, which look like static points in the sky as seen from a telescope on the ground. As a result, the stars are recorded as trails, as the Earth rotates on its axis during the exposure. In this picture, three 10 second images, taken in rapid succession on the night of the earthquake, have been overlaid. The first image (left) was started 41 seconds after the start of the earthquake, and the last (right) finishes about 100 seconds after the beginning of the earthquake. Each star is seen three times as the earthquake shakes the telescope and blurs its view of the night sky. The effect of the earthquake gradually weakens with time (towards the right of the image). The recording on the image here is similar to measurements recorded by seismographs on a roll of paper. Credit: ESO/A. Klotz (TAROT)
This image shows a comparison of the new image (top) of the western wall of the Carina Nebula taken by the international Gemini Observatory, a Program of NSF’s NOIRLab, and an image of the same region without Adaptive Optics (bottom). The top image was taken with the Gemini South telescope with the GSAOI instrument using the GeMS adaptive optics system, and the bottom image was taken at the Cerro Tololo Inter-American Observatory with the Víctor M. Blanco 4-meter Telescope using the NEWFIRM instrument. Credit: International Gemini Observatory/CTIO/NOIRLab/NSF/AURA Acknowledgment: PI: Patrick Hartigan (Rice University) Image processing: Patrick Hartigan (Rice University), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
The irregular dwarf galaxy IC 1613 contains some 100 million stars and is a member of our Local Group of galaxies, which also includes our Milky Way, the Andromeda spiral galaxy, and the Magellanic Clouds. It is at a distance of 2.4 million light-years and contains several examples of Cepheid variable stars — key calibrators of the cosmic distance ladder. The bulk of its stars were formed about 7 billion years ago and it does not appear to be undergoing star formation at the present day, unlike other very active dwarf irregulars such as the Large and Small Magellanic clouds. To the lower right of IC 1613, one may view a background galaxy cluster (several hundred times more distant than IC 1613) consisting of dozens of orange-yellow blobs, centered on a pair of giant cluster elliptical galaxies. To the left of the irregular galaxy is a bright, sixth magnitude, foreground, Milky Way star in the constellation of Cetus the Whale, identified here as a star by its sharp diffraction spikes radiating at 45-degree angles. This image is an excerpt from the Dark Energy Survey, which has released a massive, public collection of astronomical data and calibrated images from six years of work. The Dark Energy Survey is a global collaboration that includes the Department of Energy's (DOE) Fermi National Accelerator Laboratory (Fermilab), the National Center for Supercomputing Applications (NCSA), and NSF’s NOIRLab. The image was taken with the Dark Energy Camera, fabricated by DOE, on the Víctor M. Blanco 4-meter Telescope. The immensity and depth of the survey can be appreciated by diving into the zoomable version of this wider excerpt. Credit: DES/DOE/Fermilab/NCSA & CTIO/NOIRLab/NSF/AURA Acknowledgments: Image processing: DES, Jen Miller (Gemini Observatory/NSF's NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin
This image, taken with the NASA/ESA Hubble Space Telescope, shows the supernova remnant SNR 0509-68.7, also known as N103B (top of the image). N103B was a Type Ia supernova, located in the Large Magellanic Cloud — a neighbouring galaxy of the Milky Way. Owing to its relative proximity to Earth, astronomers observe the remnant to search for a potential stellar survivor of the explosion. The orange-red filaments visible in the image show the shock fronts of the supernova explosion. These filaments allow astronomers to calculate the original centre of the explosion. The filaments also show that the explosion is no longer expanding as a sphere, but is elliptical in shape. Astronomers assume that part of material ejected by the explosion hit a denser cloud of interstellar material, which slowed its speed. The shell of expanding material being open to one side supports this idea. The gas in the lower half of the image and the dense concentration of stars in the lower left are the outskirts of the star cluster NGC 1850, which has been observed by Hubble in the past [heic0108]. Credit: ESA/Hubble, NASA
Stellar Glitter in a Field of Black / Unlike a spiral or elliptical galaxy, the galaxy KK 246 looks like glitter spilled across a black velvet sheet. KK 246, also known as ESO 461-036, is a dwarf irregular galaxy residing within the Local Void, a vast region of empty space. This lonely galaxy is the only one known for certain to reside in this enormous volume, along with 15 others that have been tentatively identified. Although the picture appears to be full of galaxies, they are actually beyond this void, and instead form part of other galaxy groups or clusters. Cosmic voids, such as this one, are the spaces within the web-like structure of the Universe wherein very few or no galaxies exist. Adjacent to the Local Group, this region of empty space is at least 150 million light-years across. For perspective, our own Milky Way galaxy is estimated to be 150 000 light-years across, making this void immense in its nothingness. Credit: ESA/Hubble & NASA, E. Shaya, L. Rizzi, B. Tully, et al.
Light travels through space at just under 300 000 kilometres per second! This staggering speed is used to calculate astronomical distances; although often misinterpreted as a unit of time (due to its misleading name), a light-year is actually a unit of astronomical distance, and is defined as the distance that light travels in a year. For reference, this is around nine trillion kilometres… but it’s a little tricky to visualise! With this in mind, 15 000 light-years may sound like a truly huge distance, but compared to the vastness of the cosmos, it’s really quite nearby. In fact, an object sitting 15 000 light-years away would not even be outside our home galaxy, the Milky Way. This is roughly the distance between us and a young super star cluster known as Westerlund 1, home to one of the largest stars ever discovered. Stars are classified according to their spectral type, surface temperature, and luminosity. While studying and classifying the cluster’s constituent stars, astronomers discovered that Westerlund 1 is home to one of the largest stars ever discovered, originally named Westerlund 1-26. It is a red supergiant (although sometimes classified as a hypergiant) with a radius over 1500 times that of our Sun. If Westerlund 1-26 were placed where our Sun is in our Solar System, it would extend out beyond the orbit of Jupiter. Most of Westerlund 1’s stars are thought to have formed in the same burst of activity, meaning that they have similar ages and compositions. The cluster is relatively young in astronomical terms — at around three million years old it is a baby compared to our own Sun, which is some 4.6 billion years old. Credit: ESA/Hubble & NASA
This striking image was taken by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3, a powerful instrument installed on the telescope in 2009. WFC3 is responsible for many of Hubble’s most breathtaking and iconic photographs, including Pictures of the Week. Shown here, NGC 7773 is a beautiful example of a barred spiral galaxy. A luminous bar-shaped structure cuts prominently through the galaxy's bright core, extending to the inner boundary of NGC 7773's sweeping, pinwheel-like spiral arms. Astronomers think that these bar structures emerge later in the lifetime of a galaxy, as star-forming material makes its way towards the galactic centre — younger spirals do not feature barred structures as often as older spirals do, suggesting that bars are a sign of galactic maturity. They are also thought to act as stellar nurseries, as they gleam brightly with copious numbers of youthful stars. Our galaxy, the Milky Way, is thought to be a barred spiral like NGC 7773. By studying galactic specimens such as NGC 7773 throughout the Universe, researchers hope to learn more about the processes that have shaped — and continue to shape — our cosmic home. Credit: ESA/Hubble & NASA, J. Walsh
This image was created from ALMA data on the unusual red carbon star U Antliae and its surrounding shell of material. The colours show the motion of the glowing material in the shell along the line of sight to the Earth. Blue material lies between us and the central star, and is moving towards us. Red material around the edge is moving away from the star, but not towards the Earth. For clarity this view does not include the material on the far side of the star, which is receding from us in a symmetrical manner. Credit: ALMA (ESO/NAOJ/NRAO), F. Kerschbaum
This NASA/ESA Hubble Space Telescope Picture of the Week shows bright, colourful pockets of star formation blooming like roses in a spiral galaxy named NGC 972. The orange-pink glow is created as hydrogen gas reacts to the intense light streaming outwards from nearby newborn stars; these bright patches can be seen here amid dark, tangled streams of cosmic dust. Astronomers look for these telltale signs of star formation when they study galaxies throughout the cosmos, as star formation rates, locations, and histories offer critical clues as to how these colossal collections of gas and dust have evolved over time. New generations of stars contribute to — and are also, in turn, influenced by — the broader forces and factors that mould galaxies throughout the Universe, such as gravity, radiation, matter, and dark matter. German-British astronomer William Herschel is credited with the discovery of NGC 972 in 1784. Astronomers have since measured its distance, finding it to be just under 70 million light-years. Credit: ESA/Hubble, NASA, L. Ho
Many of the best-loved galaxies in the cosmos are remarkably large, close, massive, bright, or beautiful, often with an unusual or intriguing structure or history. However, it takes all kinds to make a Universe — as demonstrated by this Hubble Picture of the Week of Messier 110. Messier 110 may not look like much, but it is a fascinating near neighbour of our home galaxy, and an unusual example of its type. It is a member of the Local Group, a gathering of galaxies comprising the Milky Way and a number of the galaxies closest to it. Specifically, Messier 110 is one of the many satellite galaxies encircling the Andromeda Galaxy, the nearest major galaxy to our own, and is classified as a dwarf elliptical galaxy, meaning that it has a smooth and almost featureless structure. Elliptical galaxies lack arms and notable pockets of star formation — both characteristic features of spiral galaxies. Dwarf ellipticals are quite common in groups and clusters of galaxies, and are often satellites of larger galaxies. Because they lack stellar nurseries and contain mostly old stars, elliptical galaxies are often considered ‘dead’ when compared to their spiral relatives. However, astronomers have spotted signs of a population of young, blue stars at the centre of Messier 110 — hinting that it may not be so dead after all. Credit: ESA/Hubble & NASA, L.Ferrarese et al.
Deep within the glowing cloud of the HII region LHA 120-N 180B, MUSE has spotted a jet emitted by a fledgling star — a massive young stellar object . This is the first time such a jet has been observed in visible light outside the Milky Way. Usually, such jets are obscured by their dusty surroundings, meaning they can only be detected at infrared or radio wavelengths by telescopes such as ALMA. However, the relatively dust-free environment of the LMC allowed this jet — named Herbig–Haro 1177, or HH 1177 for short — to be observed at visible wavelengths. At nearly 33 light-years in length, it is one of the longest such jets ever observed. This annotated image shows a close-up of the jet source and the bow shocks formed by the jet interacting with surrounding gas. Credit: ESO, A McLeod et al.
Deep within the glowing cloud of the HII region LHA 120-N 180B, MUSE has spotted a jet emitted by a fledgling star — a massive young stellar object . This is the first time such a jet has been observed in visible light outside the Milky Way. Usually, such jets are obscured by their dusty surroundings, meaning they can only be detected at infrared or radio wavelengths by telescopes such as ALMA. However, the relatively dust-free environment of the LMC allowed this jet — named Herbig–Haro 1177, or HH 1177 for short — to be observed at visible wavelengths. At nearly 33 light-years in length, it is one of the longest such jets ever observed. The blue and red regions in this image show the jet, which was detected as blue- and red-shifted emission peaks of the Hα line. Credit: ESO, A McLeod et al.
This comparison shows the area around the Lobster and Cat’s Paw nebulae observed at different wavelengths. Top panel: submillimetre wavelengths seen by APEX. Middle panel: near-infrared wavelengths seen by ESO’s VISTA infrared survey telescope; note that regions appearing as dark dust tendrils here show up brightly in the APEX view above. Bottom panel: visible light as seen by the VST, where most of the stars are hidden from view by dusty structures. Credit: ESO/ATLASGAL consortium/VVV Survey/D. Minniti
A stunning long-exposure observation lasting 70 minutes from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, reveals the surroundings of the spiral galaxy NGC 1003 in glorious detail. NGC 1003 resides in front of a galaxy cluster — a vast collection of galaxies bound together by gravity. The long exposure time of this deep observation allowed these usually overlooked red background cluster galaxies to be captured. Credit: KPNO/NOIRLab/NSF/AURA