Picture of the Week

16 July 2018: This photograph, taken by Vincenzo Forchi, provides a unique insight into one of ESO’s most famous — and hard-working — residents. This cacophony of colour, structure and machinery is the interior of the 8.2-metre Unit Telescope 1 (UT1) of ESO’s Very Large Telescope (VLT), at Paranal Observatory in northern Chile. UT1 is more charmingly named Antu, which means The Sun in the region’s indigenous Mapuche language. The other UTs are named after the Moon, the Southern Cross, and Venus — Kueyen, Melipal, and Yepun respectively. Forchi’s image shows Antu as it blinks open its high-tech eye and prepares for a long night observing the cosmos. At the base of the building, artificial lights bathe the area with an incandescent yellow glow. Above, the blue and silver hues of the telescope’s metalwork are complemented by the warm orange embrace of the Sun’s final rays, which scatter off the numerous flaps, or ...

9 July 2018: This photo montage shows a familiar cosmic object — the Moon — in a very unfamiliar way. ESO Photo Ambassador Petr Horálek captured this photoset while visiting ESO’s high-altitude Paranal Observatory in Chile, where skies are remarkably clear. He snapped photographs of this striking blood-red moonset at five-second intervals, watching as the Moon sank through the dark sky before finally dipping below the horizon (the frames are ordered chronologically from left to right, and top to bottom). The prominent red colour of these images is due to the phenomenon of atmospheric refraction. As the Moon approaches the horizon, its reflected light must traverse more and more of the atmosphere before reaching our eyes, meaning that scattering becomes more prominent — in other words, there is more air for the light to push through, and more light is scattered. Of all the colours of visible light, the Earth’s atmosphere scatters and ...

2 July 2018: This image from the Atacama Large Millimeter/submillimeter Array (ALMA) shows MWC 758, a young star that is approaching adulthood and surrounded by knotty, irregular rings of cosmic dust, three of which can be seen here. Unusually, these rings are elliptical in shape rather than being perfectly circular — making this the first discovery of an intrinsically elliptical protoplanetary disc with ALMA! The outer and inner rings each contain one particularly bright clump, visible as arcs of yellow. Additionally there appear to be spiral arms traced out within the dust, as well as a core dust-free cavity that is slightly off-centre. These are all features that hint at the presence of unseen planets. As planets form, they gravitationally interact with the disc and create various telltale features and structures. Astronomers can thus observe a system like MWC 758 and not only infer the existence of potential hidden planets, but also estimate ...

25 June 2018: Sitting between Mars and Jupiter, the doughnut-shaped asteroid belt is packed full of rocky bodies and debris. Despite its fragmented, rubbly nature, the total mass contained within the belt is considerable — roughly four per cent of that of the Moon! The majority of this mass is contained within two distinctive bodies: Ceres, a dwarf planet estimated to make up a third of the mass of the belt, and the asteroid Vesta, which holds around nine per cent of it. Vesta is pictured here. Vesta was recently observed by the SPHERE/ZIMPOL instrument on ESO’s Very Large Telescope (VLT) — the SPHERE image is shown on the left (see the single image here), produced using the MISTRAL algorithm, with a synthetic view derived from space-based data shown on the right for comparison. SPHERE, the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument, is a powerful planet-finding and direct imaging instrument. ZIMPOL is one of ...

18 June 2018: In this spectacular shot from northern Chile, the immediately recognisable and magnificent constellation of Orion (The Hunter) peers down on the small walkway connecting ESO’s 3.6-metre telescope to the now-decommissioned Coudé Auxiliary Telescope, both located at ESO’s La Silla Observatory. A closer look at this long exposure, captured by ESO Photo Ambassador Yuri Beletsky, reveals many interesting features — including a streak of light as an artificial satellite passes behind the telescope’s dome (to the right of the frame). Barnard’s Loop, a faint emission nebula thought to be the remnant of a supernova, appears as a faint reddish arc encircling the bright Orion Nebula. Just below and parallel to the walkway, the dark dust lanes of the Milky Way can be seen rippling across the starry sky. ESO’s 3.6-metre telescope is equipped with the High Accuracy Radial velocity Planet Searcher (HARPS) instrument, one of the most accurate and productive planet ...

11 June 2018: Many telescopes are formed of multiple mirrors or antennas, not just one. ESO’s Very Large Telescope (VLT), located at ESO’s Paranal Observatory in Chile, is a prime example. The VLT comprises four main telescopes, and four smaller, movable auxiliary telescopes — eight individual structures in total. However, even this is dwarfed by the Atacama Large Millimeter/submillimeter Array (ALMA), which sits atop the Chajnantor plateau in the Chilean Andes — and comprises a whopping 66 antennas! Even individually, the ALMA antennas are impressive in size. The Chajnantor plateau itself is also located at an altitude of 5000 metres, with its Operations Support Facility (OSF) at a (still considerable) altitude of 2900 metres. As the antennas are not built up on the plateau, this required an entirely new approach to transporting each of the constituent antennas from the OSF up to Chajnantor. Enter Otto and Lore! Designed and built especially for the ...

4 June 2018: ESO’s La Silla observatory in Chile is unavoidably photogenic from every angle — including unusual and creative perspectives such as this one! This unique panoramic view was captured by ESO Photo Ambassador Petr Horálek. “I was wondering if it was possible to capture the mystical colours of the Universe without complicated equipment,” he explained, adding that he was initially inspired by one of the posters released to accompany Christopher Nolan’s film Interstellar. “At La Silla, you can really feel — and capture — interstellar moments!” Petr evidently succeeded in imaging the Universe in all its beauty. The majestic band of the Milky Way galaxy blazes across the sky, creating a cosmic bridge between two of La Silla’s resident telescopes: the ESO 3.6-metre telescope (left) and the Swedish-ESO Submillimetre Telescope (right). The Large and Small Magellanic Clouds — a duo of nearby galaxies — are captured together sitting “above” the galactic ...

28 May 2018: 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 ...

21 May 2018: Two spiral galaxies are locked in a spellbinding, swirling dance in this image from the VIMOS instrument on ESO’s Very Large Telescope (VLT). The two interacting galaxies — NGC 5426 and NGC 5427 — together form an intriguing astronomical object named Arp 271, the subject of this, the final image captured by VIMOS before it was decommissioned on 24 March 2018. VIMOS — or, in full, the VIsible Multi-Object Spectrograph — was active on the VLT for an impressive 16 years. During that time it helped scientists to uncover the wild early lives of massive galaxies, observe awe-inspiring triple-galaxy interactions, and explore deep cosmic questions such as how the Universe’s most massive galaxies grew so large. Instead of focusing on single objects, VIMOS was able to capture detailed information about hundreds of galaxies at once. This sensitive instrument collected the spectra of tens of thousands of galaxies throughout the Universe, ...

14 May 2018: Twinkling stars are far more desirable to poets and romantics than to astronomers. Even in the near-pristine seeing conditions over Chile, home to ESO’s fleet of world-class telescopes, turbulence in Earth’s atmosphere causes stars to twinkle, blurring our view of the night sky. These four laser beams are specially designed to combat this turbulence. The intense orange beams dominating this image originate from the 4 Laser Guide Star Facility, a state-of-the-art component of the Adaptive Optics Facility of ESO’s Very Large Telescope (VLT). Each beam is some 4000 times more powerful than a standard laser pointer! Each creates an artificial guide star by exciting sodium atoms high in the Earth’s upper atmosphere and causing them to glow. Creating artificial guide stars allows astronomers to measure and correct for atmospheric distortion, by adjusting and calibrating the settings of their observing equipment to be as accurate as possible for that particular area ...

7 May 2018: In an astronomically unlikely coincidence, a star exploded as a nova in the sky over the Supernova Planetarium & Visitor centre less than a week after its inauguration. An image of the dwarf nova V392 Persei was captured by ESO photo ambassador Petr Horálek on 2 May 2018. It shows a wide angle view of the evening sky over the ESO Supernova, looking west-northwest. The position of the nova over the ESO Supernova is marked on the wide view with an insert showing a zoomed view of the area taken with same camera but using a different lens. In this image the nova is easily identifiable due to its typical orange colour. Dwarf novae occur as a result of a white dwarf star accreting material from its lower mass, binary companion. The material from the disc is compressed as it is transferred to the surface of the white dwarf where ...

30 April 2018: A sinister smile appears amid a sea of stars in this image — a small portion of a gigantic gigapixel colour mosaic of the Milky Way’s heart. Comprised of thousands of incredibly detailed images taken by ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA), the mosaic reveals more of the stars at the Milky Way’s heart than ever before. VISTA was chosen due to its extremely sensitive infrared camera, which can see through most of the dust that blocks our view towards the centre of the galaxy. What we see in this image is a dense patch of gas and dust — a nebula — that even VISTA’s camera cannot see through. Located near the Lagoon Nebula (not seen), it appears to wink back as it mischievously blocks out the light from background stars. The full image contains almost nine billion pixels, and is part of the Vista Variables ...

23 April 2018: This unusual image shows three of the telescopes sited at ESO’s La Silla observatory in Chile — the MPG/ESO 2.2-metre telescope on the left, ESO’s 3.6-metre telescope sitting in the distance behind it, and the Danish 1.54-metre telescope on the right, apparently looming over its companions in the foreground. Of course, this is a highly distorted view of the telescopes! This photograph was taken by ESO Photo Ambassador Petr Horálek to emphasise not the telescopes themselves but the stunning features of the night sky above the observatory site, which is one of the best in the world. This is a long-exposure shot intended to capture the apparent motion of the stars as they circle slowly overhead in the sky. Over time, the stars appear to drag out trails of light in the sky — known as star trails — painting large circles onto the dark cosmos (this phenomenon is actually ...

16 April 2018: This breathtaking view of ESO’s Paranal Observatory reveals a spectacular night scene over part of ESO’s Very Large Telescope (VLT), the observatory’s most famous resident. The telescope sitting centre stage is one of the VLT’s four Unit Telescopes (UT). The VLT comprises both these UTs and four additional, movable, Auxiliary Telescopes (ATs). However impressive the VLT may be, the closed telescope is trumped in this image by the skies overhead — most prominently by the colourful plane of our home galaxy, the Milky Way, as it arches across the frame and creates a celestial rainbow. Part of the sky is tinted a faint green colour due to a phenomenon known as airglow, and the two smudges of the Magellanic Clouds can be seen to the left of the UT. The famous constellation of Orion (The Hunter) is visible to the right of centre, the bright stars of which can be ...

9 April 2018: Light travels to the telescopes at ESO’s La Silla Observatory in Northern Chile over vast distances, from the planets and moons within the Solar System, and from the distant stars of the Milky Way and beyond. This spectacular Ultra High Definition panorama of the observatory, created by ESO Photo Ambassador Babak A. Tafreshi, captures light from a wide range of celestial objects. Two of the most prominent sources of light in this spectacular shot are the Large and Small Magellanic Clouds, which can be seen as two diffuse fuzzy patches at the centre of the photo. These two galaxies are located 160 000 and 200 000 light-years away from us. The nearest celestial object in this starry scene is Mars, shining next to the open dome of the 1.54-metre Danish telescope in the foreground. At the time of this photograph, the red planet was 93 million kilometres from Earth. Venus, ...

2 April 2018: This unique image from ESO’s VLT Survey Telescope (VST) reveals two galaxies at the very beginning of the merging process. The interactions between the duo have created a rare effect known as a light echo, where light reverberates around the material within each galaxy. This is analogous to the acoustic echo where the reflected sound arrives at the listener with a delay after the direct sound. This is the first case of a light echo observed between two galaxies. The larger galaxy, seen here in yellow, is ShaSS 073 — an active galaxy with an extremely luminous core. Its less massive companion, in blue, is named ShaSS 622, and together the pair make up the intriguing ShaSS 622-073 system. The bright core of ShaSS 073 is exciting a region of gas within the disc of its blue companion: it bombards the material there with radiation, causing it to glow brightly ...

26 March 2018: This week’s featured image highlights a handful of the telescopes residing at ESO’s La Silla Observatory in northern Chile. The star of the show, framed perfectly by the beautiful arch of the Milky Way, sits directly in the middle of the photograph — the Danish 1.54-metre telescope. Operational since 1979, this trusty telescope has helped astronomers to make all kinds of cosmic discoveries, from understanding more about violently merging neutron stars to detecting planets around other stars. It now performs follow-up observations of gamma-ray bursts, some of the most energetic events in the Universe. This image, taken by ESO Photo Ambassador Petr Horálek, shows the heart of the Milky Way, both the Large and Small Magellanic Clouds, the constellations of Orion (The Hunter) and the Southern Cross, and the glare of distant settlements, all of which create vibrant bursts and flashes of colour across the frame. Towards the distant horizon, ...

19 March 2018: This spectacular shot from ESO’s La Silla Observatory in Chile was captured by by ESO Photo Ambassador Yuri Beletsky, and reveals all manner of astronomical treats! The central plane of our galaxy stretches, slightly curved, across the frame, peppered with bright patches of gas and dark, weaving dust lanes. Although initially a little hard to see against the intricate cosmic backdrop, the constellation of Orion (The Hunter) can be seen to the top left of the frame. Multiple pink clouds, produced by the faint glow of ionised hydrogen gas, appear to extend beyond the band of the Milky Way, indicating the presence of hot, young new stars. One of these areas is Barnard's Loop, which encircles the famous Orion Nebula and can be seen curving around Orion’s Belt. The MPG/ESO 2.2-metre telescope sits beneath the colourful night sky, where it is currently involved in research chasing the aftermath of some ...

12 March 2018: A sweeping blanket of stars gazes serenely down over Cerro Paranal, Chile, as the rising Sun gently warms the horizon with splashes of red and yellow. Cerro Paranal is home to ESO’s Very Large Telescope (VLT) — and this striking panorama reveals the telescope in all its glory. All four of the VLT’s large 8.2-metre Unit Telescopes are visible along the left side of the image, lined up and ready to explore the Universe. Two smaller 1.8-metre Auxiliary Telescopes can be seen scattered across the right side of the frame; the VLT has four of these in total, all of which are movable along a grid of tracks, and can be rearranged as needed. In the distance, the 2.6-metre VLT Survey Telescope (VST) — the newest addition to Paranal — can be seen just beyond the rightmost Unit Telescope. Above and between the two leftmost Unit Telescopes, the mighty extent ...

5 March 2018: All of ESO’s observatories are based in Chile, but the organisation’s headquarters, and the newest exciting addition sits in Garching, a small city near Munich in Germany. This image shows a striking and unusual view of this new member of the ESO family — the ESO Supernova Planetarium & Visitor Centre. The ESO Supernova has its official inauguration event on 26 April and will open for the public on 28 April. At its heart, the Supernova is a truly state-of-the-art planetarium that will visualise and project accurate, awe-inspiring, and fully immersive views of the Universe for audiences to enjoy. The building also houses a cutting-edge astronomy centre and exhibition space. To make things even more appealing, attendance and all activities will be free throughout 2018! This image was taken by ESO Photo Ambassador Petr Horálek, reveals the curved arms of ESO headquarters reaching out toward the unique Supernova building, below ...