Photo de la semaine

10 février 2014: Perched precariously on the edge of the habitable world, life manages to cling on. On the outskirts of the hot, dry Atacama Desert, this hardy South American grey fox has just awoken, stretching leisurely. These foxes are generally active during the night, making the most of the drop in temperature that comes with a respite from the hot Chilean Sun. In the background there are other signs of life. This white dome houses the Swiss 1.2-metre Leonhard Euler Telescope, which is protected from the harsh conditions by its outer shell. As the skies grow darker at ESO’s La Silla Observatory another famously nocturnal species, the astronomer, wakes up, stretches, and gets ready to scan the skies with buzzing and whirring technology. This image was taken by ESO Photo Ambassador Malte Tewes and submitted to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos ...

3 février 2014: This beautiful panorama of ESO's Paranal Observatory was taken on 5 July 2012, and marks one of the driest days ever recorded at the Very Large Telescope complex. Paranal sits like an island in the middle of the frame, with massive cloud banks floating below, over the distant Pacific Ocean. The extremely low humidity at Paranal during this period was recorded by a water vapour radiometer known as LHATPRO, which monitors the atmosphere to support the observations carried out at the observatory [1]. Meteorologists from two Chilean universities identified the cause for these unusually dry conditions: high-altitude Antarctic air moving far to the north, and descending over Paranal. This cold front lingered around Paranal for over 12 hours, causing a record-low level of humidity in the air above the observatory [2]. Florian Kerber (ESO) and colleagues analysed this unusual weather, publishing the results in a paper in the Monthly Notices ...

27 janvier 2014: Astronomers do not always swim at the swimming pool at the Paranal Observatory Residencia, but when they do, they like to show how physical principles work. In this picture the French ESO astronomer Jean-Baptiste Le Bouquin is demonstrating how waves — not light waves, but water waves — can combine, or interfere, to create larger waves. The combination of light waves is the main principle behind the VLT Interferometer: the light waves captured by each one of the four 8-metre telescopes are combined using a network of channels and mirrors. This way the spatial resolution of the telescope is vastly increased and, with enough exposure time, the cameras and instruments can reveal the same level of detail as a telescope with a 130-metre diameter mirror could, far bigger than any telescope in existence. This image was taken by award-winning editorial and commercial photographer Max Alexander. See also Tribute to ESO’s ...

20 janvier 2014: ESA's Rosetta spacecraft will wake up today, 20 January, after 31 months in deep space hibernation, to finally close in on comet 67P/Churyumov-Gerasimenko (67P/CG). This image shows the most recent observations of the 4-kilometre diameter comet, taken on 5 October 2013 by ESO's Very Large Telescope (VLT) when the comet was around 500 million kilometres away — before it passed behind the Sun and out of view from Earth's perspective. For this image, a long series of observations was processed to reveal both the comet without the background stars (on the left panel), and the star field with the track of the comet marked (on the right). Viewed against a crowded star field towards the centre of the Milky Way, the comet was still so far from the Sun that the icy nucleus was not releasing any gas or dust, and appears as a simple spot. As it approaches the ...

13 janvier 2014: Thanks to ESO’s Photo Ambassadors we can enjoy sensational images taken at the ESO sites on the remote mountaintops of Chile. Babak Tafreshi has captured this fine panoramic view of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) at twilight. Resembling a frame from a science fiction movie, the technological spectacle of ALMA against the raw natural power of the landscape on the Chajnantor Plateau, 5000 metres above sea level, results in fascinating images like this one. There are a few details you shouldn't miss in this panoramic photo of ALMA (seen more clearly in the zoomable version), all lying between the two groups of antennas: the "Earth's shadow" and "Belt of Venus" phenomena, visible as the dark blue and light pink bands stretching across the sky, and the planet Jupiter, seen right above the mountain in the background. ALMA, an international astronomy facility, is a partnership of Europe, ...

6 janvier 2014: Admirez le ciel nocturne depuis l'observatoire Paranal de l'ESO au Chili, et vous serez accueillis par une vue époustouflante comme celle-ci. Des taches de bleu, d'orange, de rouge, chacune étant une étoile, une galaxie ou une nébuleuse différente, ou plus, formant ensemble un ciel étincelant. Les astronomes observent cette magnifique toile de fond et tentent de percer les mystères de l'Univers. Pour ce faire, ils utilisent des télescopes comme ceux qui sont montrés ici, les télescopes auxiliaires VLT. Cette image montre trois des quatre unités mobiles qui alimentent en lumière le Very Large Telescope Interferometer, l'instrument optique le plus avancé au monde. En se combinant pour former un plus grand télescope, elles sont plus grandes que la somme de leurs parties : elles révèlent des détails qui seraient visibles avec un télescope aussi grand que la distance qui les sépare.

30 décembre 2013: When night falls, ESO's observatories spring to life. Astronomers and technicians take their positions, and telescopes are pointed skywards. This image shows the pristine skies over ESO's Paranal Observatory in the Chilean Atacama Desert, far away from city lights. Here, ESO photo ambassador Gabriel Brammer has captured the serene beauty of the Milky Way from the platform of the Very Large Telescope. The four massive blocks in the bottom of the image are the four VLT Unit Telescopes, each of them housing incredibly precise 8.2-metre mirrors. Scattered around are the VLT's Auxiliary Telescopes, easily identifiable due to their round, white domes. The bright spot to the left is the Moon, shining as brightly as if it were the Sun, and to the right, the shadow of the photographer can be seen, waving to the viewer with outstretched arms. The entire night sky is visible due to Brammer's use of a ...

23 décembre 2013: Season's Greetings on behalf of everyone at the European Southern Observatory! We wish you a jolly end of the year and a fruitful 2014! Link Christmas card 2013

16 décembre 2013: This image was taken by Babak A. Tafreshi, one of ESO’s Photo Ambassadors, at ESO’s Paranal Observatory. It shows three of the four Auxiliary Telescopes (ATs) of the Very Large Telescope Interferometer (VLTI). Above them, the long bright stripes are star trails, each one marking the apparent path of a single star across the dark night sky, due to the rotation of the Earth. This technique also enhances the natural colours of the stars, which gives an indication of their temperature, ranging from about 1000 degrees Celsius for the reddest stars to a few tens of thousands of degrees Celsius for the hottest, which appear blue. The sky in this remote and high location in Chile is extremely clear and there is no light pollution, offering us this amazing light show.

9 décembre 2013: Alpha and Beta Centauri, two of the brightest stars in the southern sky, had a new companion in late 2013 — the naked eye Nova Centauri 2013. This photo was taken by ESO Photo Ambassador Yuri Beletsky at ESO's La Silla Observatory in the Chilean Atacama Desert in the morning hours of Monday 9 December 2013. The nova was discovered by John Seach from Australia on 2 December 2013 as it approached naked eye brightness. Nova Centaurus 2013 is the brightest nova to have occurred so far this millennium. This particular event is known as a classical nova, and is not to be confused with a supernova. Classical novae occur in binary star systems when hydrogen gas from the orbiting stellar partner is accreted onto the surface of the main star, causing a runaway thermonuclear event resulting in the brightening of the main star. In a classical novae the main ...

2 décembre 2013: This impressive photograph, taken at the site of ESO’s Very Large Telescope (VLT) at Paranal Observatory in Chile, shows, towards the centre left, the Milky Way — with its share of nebulae, stars, and gas clouds — rising above the VLT Unit Telescopes. To the right, competing for attention as it arcs above the horizon, a beautiful, almost triangular band of diffuse light lies along the ecliptic, which is the apparent path of the Sun in the sky as seen from the Earth. This glow originates in the scattering of sunlight by dust located between the planets that are spread through the plane of the Solar System. This coincides in the sky with the band known as the Zodiac, which extends for eight degrees of arc on either side of the ecliptic and contains the traditional zodiacal constellations.

25 novembre 2013: Babak Tafreshi, one of the ESO Photo Ambassadors, has captured the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) in an enthralling image combining the beauty of the southern sky with the amazing dimensions of the biggest astronomical project in the world. Thousands of stars are revealed to the naked eye in the clear skies over the Chajnantor Plateau. Its dry and transparent night sky is one of the reasons ALMA has been built here. Surprisingly bright in the upper left corner of the picture, there is a tightly packed bunch of young stars, the Pleiades Cluster, which was already known to most ancient civilisations. The constellation of Orion (The Hunter) is clearly visible over the closest of the antennas — the hunter’s belt is formed by the three blue stars just to the left of the red light. According to classic mythology, Orion was a hunter who chased the ...

18 novembre 2013: Cette nouvelle vue de la comète C/2012 S1 (ISON) a été prise avec le télescope national TRAPPIST-South à l'observatoire de La Silla de l'ESO dans la matinée du vendredi 15 novembre 2013. La comète ISON a été aperçue pour la première fois dans notre ciel en septembre 2012, et fera son approche la plus proche du Soleil fin novembre 2013. TRAPPIST-South surveille la comète ISON depuis la mi-octobre, en utilisant des filtres à large bande comme ceux utilisés dans cette image. Il utilise également des filtres spéciaux à bande étroite qui isolent l'émission de divers gaz, permettant ainsi aux astronomes de compter le nombre de molécules de chaque type qui sont libérées par la comète. La comète ISON a été assez calme jusqu'au 1er novembre 2013, date à laquelle une première explosion a doublé la quantité de gaz émis par la comète. Le 13 novembre, juste avant la prise de ...

11 novembre 2013: ESO Photo Ambassador, Babak Tafreshi captured this panoramic view of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) under the clear sky over the Chajnantor Plateau, in the Chilean Andes. The rosy patch prominent at the left of the image is the Carina Nebula. It lies in the constellation of Carina (The Keel), about 7500 light-years from Earth. This cloud of glowing gas and dust is the one of brightest nebulae in the sky and contains several of the brightest and most massive stars known in the Milky Way, such as Eta Carinae. For some beautiful recent images of the Carina Nebula from ESO, see eso1208, eso1145, and eso1031. ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by ...

4 novembre 2013: On a dark September night at ESO’s La Silla Observatory, after spending the night at the telescope, astronomer Klaas Wiersema was returning to the restaurant. Most of the work at an observatory takes place at night, so it is not rare to have scientists and technicians walking around in the darkness. This time, something unexpected happened. Suddenly, Klaas heard a loud snort behind him and the sound of massive feet chasing him. He was convinced that some kind of angry animal had emerged from its lair and was trying to hunt him down, so he ran like the wind. He couldn’t imagine what kind of beast was chasing him on the desolate slopes of the Atacama Desert, at 2400 metres above sea level, so he spent the rest of the night trying figure out the mystery. When daylight came he went exploring, only to find that he had passed too ...

28 octobre 2013: In this ghostly night picture, taken at Paranal Observatory, we can see three out of four VLT Auxiliary Telescopes. Each one of them is a 1.8-metre telescope designed to work along with the other three as a single telescope, thanks to the VLT Interferometer. In the background, the quiet beauty of the Atacama sky is enhanced by a red aurora-like shimmer, called airglow, which is caused by light-emitting chemical reactions in the atmosphere. Normally, those emissions are not so strong, but the night this image was taken they were unusually bright, producing this unusual picture.

21 octobre 2013: This stunning image of the clear Chilean sky shows a speckling of bright stars and distant galaxies across the frame, all suspended above one of the four Unit Telescopes (UTs) of the Very Large Telescope (VLT). This is the fourth UT and it is known as Yepun (Venus). Two objects seen in this frame are more famous than their neighbours. In the left hand portion of the image is a fairly prominent galaxy that forms a streak across the sky — Messier 31, or the Andromeda Galaxy. Upwards and to the right of this smudge is a bright star, which in turn points upwards to a galaxy that lies roughly along the same extended line. This star is named Beta Andromedae — otherwise known as Mirach — and the second galaxy is Messier 33 (at the top of the frame). These two galaxies are thought to have interacted in the ...

14 octobre 2013: This new picture from the VLT Survey Telescope (VST) at ESO's Paranal Observatory shows the remarkable super star cluster Westerlund 1 (eso1034). This exceptionally bright cluster lies about 16 000 light-years from Earth in the southern constellation of Ara (The Altar). It contains hundreds of very massive and brilliant stars, all of which are just a few million years old — babies by stellar standards. But our view of this cluster is hampered by gas and dust that prevents most of the visible light from the cluster's stars from getting to Earth. Now, astronomers studying images of Westerlund 1 from a new survey of the southern skies [1] have spotted something unexpected in this cluster. Around one of the stars — known as W26, a red supergiant and possibly the biggest star known— they have discovered clouds of glowing hydrogen gas, shown as green features in this new image. Such ...

7 octobre 2013: This image shows a dark Chilean sky filled with spectacular star trails — caused by the Earth's rotation during the camera's long exposure time. Underneath these dramatic streaks lies the Paranal Residencia, an oasis to the staff and visitors to ESO's Very Large Telescope, located high on Cerro Paranal in the Chilean desert. Construction of the Residencia began in 1998 and was completed by 2002. Since then, it has offered a welcome break from the harsh, dry climate of the desert to the scientists and engineers who work at Paranal Observatory. The four-storey building has the majority of its structure buried underground. The facility was designed by German architects Auer+Weber to complement the surrounding environment. From certain angles, the combination of hi-tech utilitarian architecture and inconspicuous, almost camouflage-like design is reminiscent of a villain’s secret lair. Perhaps it is no surprise that the Residencia was selected as the setting for ...

30 septembre 2013: This frame, scattered with distant stars and galaxies, is a deep-field image taken using the Wide Field Imager (WFI), a camera mounted on the MPG/ESO 2.2-metre telescope located at the La Silla Observatory, Chile. It was snapped as part of the COMBO-17 survey (Classifying Objects by Medium-Band Observations in 17 filters), a project that imaged five small patches of sky in 17 different coloured optical filters. The total area of sky explored in each of the COMBO-17 fields equates to approximately the same size as the full Moon, and has revealed huge numbers of distant objects — demonstrating just how much is still waiting to be discovered in our skies. The image shows a region that was also investigated as part of the FORS Deep Field (FDF), a project that examined various areas of sky in great detail and depth using the FORS2 spectrograph instrument currently installed on ESO’s Very ...