Picture of the Week 2012

31 December 2012: Babak Tafreshi, one of the ESO Photo Ambassadors, has captured the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) under the southern sky in another breathtaking image. The dramatic whorls of stars in the sky are reminiscent of van Gogh’s Starry Night, or — for science fiction fans — perhaps the view from a spacecraft about to enter hyperspace. In reality, though, they show the rotation of the Earth, revealed by the photograph’s long exposure. In the southern hemisphere, as the Earth turns, the stars appear to move in circles around the south celestial pole, which lies in the dim constellation of Octans (The Octant), between the more famous Southern Cross and the Magellanic Clouds. With a long enough exposure, the stars mark out circular trails as they move. The photograph was taken on the Chajnantor Plateau, at an altitude of 5000 metres in the Chilean Andes. This is the ...

24 December 2012: This panoramic view of the Chajnantor Plateau shows the site of the Atacama Large Millimeter/submillimeter Array (ALMA), taken from near the peak of Cerro Chico. Babak Tafreshi, an ESO Photo Ambassador, has succeeded in capturing the feeling of solitude experienced at the ALMA site, 5000 metres above sea level in the Chilean Andes. Light and shadow paint the landscape, enhancing the otherworldly appearance of the terrain. In the foreground of the image, clustered ALMA antennas look like a crowd of strange, robotic visitors to the plateau. When the telescope is completed in 2013, there will be a total of 66 such antennas in the array, operating together. ALMA is already revolutionising how astronomers study the Universe at millimetre and submillimetre wavelengths. Even with a partial array of antennas, ALMA is more powerful than any previous telescope at these wavelengths, giving astronomers an unprecedented capability to study the cool Universe — ...

17 December 2012: ESO Photo Ambassador, Babak Tafreshi has taken another outstanding panoramic photograph of ESO’s Paranal Observatory. In the foreground is the dramatic, mountainous landscape of the Atacama Desert. On the left, on the highest peak, is the ESO Very Large Telescope (VLT), and in front of it, on a slightly lower peak, is the VISTA telescope (Visible and Infrared Survey Telescope for Astronomy). In the background, the sunrise colours Paranal’s sky with a beautiful pastel palette. Extending beyond the horizon, the sea of clouds over the Pacific Ocean — which lies only 12 kilometres from Paranal — is visible. Above the horizon, where the sea of clouds meets the sky, a dark band can be seen. This dark band is the Earth’s shadow, cast by the planet onto its atmosphere. This phenomenon can sometimes be seen around the times of sunset and sunrise, if the sky is clear and the horizon ...

10 December 2012: Although this image might at first look like abstract modern art, it is in fact the result of a long camera exposure of the night sky over the Chajnantor Plateau in the Chilean Andes. As the Earth rotates towards another day, the stars of the Milky Way above the desert stretch into colourful streaks. The high-tech telescope in the foreground, meanwhile, takes on a dreamlike quality. This mesmerising photo was taken 5000 metres above sea level on the Chajnantor Plateau, home of the Atacama Pathfinder Experiment (APEX) telescope, which is seen here. APEX is a 12-metre-diameter telescope which collects light with wavelengths in the millimetre and submillimetre range. Astronomers use APEX to study objects ranging from the cold clouds of gas and cosmic dust where new stars are being born, to some of the earliest and most distant galaxies in the Universe. APEX is a pathfinder for the Atacama Large ...

3 December 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO facilities in Santiago de Chile, and the Headquarters in Garching bei München, Germany.The Very Large Telescope (VLT), ESO’s flagship facility on Cerro Paranal in Chile, is made up of four giant Unit Telescopes (UTs), each sporting a mirror of 8.2-metre diameter, and four movable 1.8-metre Auxiliary Telescopes. Our pair of photographs this month shows a Unit Telescope under construction, and one in the present day.Early work on the first Unit Telescope (UT1) enclosure can be seen in the historical image, taken in late October 1995. The concrete foundations were complete and the lower, stationary part of the enclosure’s ...

26 November 2012: For centuries, philosophers and scientists have wondered about the possibility of habitable planets outside the Solar System. Today, this idea is more than speculation: many hundreds of exoplanets have been discovered over the last couple of decades, by astronomers all over the world. Various different techniques are used in this search for new worlds. In this unusual photograph, telescopes using two of these methods, the ESO 3.6-metre telescope with the HARPS spectrograph, and the space telescope CoRoT, have been captured in the same shot. The photograph was taken by Alexandre Santerne, an astronomer who studies exoplanets himself. The High Accuracy Radial velocity Planetary Search (HARPS) spectrograph, the world’s foremost exoplanet hunter, is an instrument on ESO’s 3.6-metre telescope. The open dome of this telescope can be seen on the left of this image, behind the angular enclosure of the New Technology Telescope. HARPS finds exoplanets by detecting small changes in ...

19 November 2012: The Atacama Pathfinder Experiment (APEX) telescope — captured in this dramatic image taken by ESO Photo Ambassador Babak Tafreshi — is one of the tools used by ESO to peer beyond the realm of visible light. It is located on the Chajnantor Plateau at an altitude of 5000 metres. Clusters of white penitentes can be seen in the foreground of the photograph. The penitentes (Spanish for penitents) are a curious natural phenomenon found in high altitude regions, typically more than 4000 metres above sea level. They are thin spikes of hardened snow or ice, with their blades pointing towards the Sun, attaining heights from a few centimetres up to several metres. APEX is a 12-metre-diameter telescope that observes light at millimetre and submillimetre wavelengths. Astronomers observing with APEX can see phenomena which would be invisible at shorter wavelengths. The telescope enables them to study molecular clouds — the dense regions ...

12 November 2012: ESO Photo Ambassador, Babak Tafreshi has captured an outstanding image of the sky over ESO’s Paranal Observatory, with a treasury of deep-sky objects. The most obvious of these is the Carina Nebula, glowing intensely red in the middle of the image. The Carina Nebula lies in the constellation of Carina (The Keel), about 7500 light-years from Earth. This cloud of glowing gas and dust is the brightest nebula in the sky and contains several of the brightest and most massive stars known in the Milky Way, such as Eta Carinae. The Carina Nebula is a perfect test-bed for astronomers to unveil the mysteries of the violent birth and death of massive stars. For some beautiful recent images of the Carina Nebula from ESO, see eso1208, eso1145, and eso1031. Below the Carina Nebula, we see the Wishing Well Cluster (NGC 3532). This open cluster of young stars was named because, through ...

5 November 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO facilities in Santiago de Chile, and the Headquarters in Garching bei München, Germany. In this month’s pair of photographs, taken at ESO’s Paranal Observatory in Chile’s Atacama Desert, we compare a bustling construction site, as seen in November 1999, with the end result in the present day: the observatory’s accommodation building, known as the Paranal Residencia. Imagine the change from then to now: the clanging of hammers and drills, and the noise of tractors and cranes, have given way to the peaceful calm of a desert building that complements its surroundings. Built using natural materials and colours, and ...

29 October 2012: This beautiful panoramic picture taken by Babak Tafreshi, an ESO Photo Ambassador, shows the last rays of sunlight bathing the Chajnantor Plateau in Chile’s Atacama region. The plateau is the home of the Atacama Pathfinder Experiment (APEX) telescope, which can be seen on the left of the panorama. From this remote place on Earth, 5000 metres above sea level, APEX studies the “cold Universe”. APEX is a 12-metre-diameter telescope that observes light at millimetre and submillimetre wavelengths. Astronomers observing with APEX can see phenomena which would be invisible at shorter wavelengths. The telescope enables them to study molecular clouds — the dense regions of gas and cosmic dust where new stars are being born — which are dark and obscured by dust in visible or infrared light, but which glow brightly at these relatively longer wavelengths. Astronomers use this light to study the chemical and physical conditions in the clouds. ...

22 October 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO facilities in Santiago de Chile, and the Headquarters in Garching bei München, Germany. Since December 2009 the Visible and Infrared Survey Telescope for Astronomy (VISTA) has been mapping the southern sky from ESO’s Paranal Observatory in Chile. Our pair of photographs this month shows the VISTA telescope, during construction and in the present day. The historical image, taken in mid-to-late 2004, shows the telescope’s building under construction. The skeleton of the telescope enclosure is visible on its circular base, surrounded by a temporary cage of scaffolding. VISTA sits on a peak about 1500 metres northeast of Cerro Paranal, ...

15 October 2012: IC 5148 is a beautiful planetary nebula located some 3000 light-years away in the constellation of Grus (The Crane). The nebula has a diameter of a couple of light-years, and it is still growing at over 50 kilometres per second — one of the fastest expanding planetary nebulae known. The term “planetary nebula” arose in the 19th century, when the first observations of such objects — through the small telescopes available at the time — looked somewhat like giant planets. However, the true nature of planetary nebulae is quite different. When a star with a mass similar to or a few times more than that of our Sun approaches the end of its life, its outer layers are thrown off into space. The expanding gas is illuminated by the hot remaining core of the star at the centre, forming the planetary nebula, which often takes on a beautiful, glowing shape. ...

8 October 2012: ESO’s Paranal Observatory — located in Chile’s Atacama region — is most well known for the Very Large Telescope (VLT), ESO’s flagship telescope facility. However, over the last few years, the site has also become home to two state-of-the-art survey telescopes. These new members of the Paranal family are designed to image large areas of the sky quickly and deeply. One of them, the 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), is located on a neighbouring peak not far from the Paranal summit. It is shown in this beautiful photograph taken from Paranal by ESO Photo Ambassador, Babak Tafreshi. VISTA is the world’s largest survey telescope, and has been operating since December 2009. At the lower right corner of the image, VISTA’s enclosure appears in front of a seemingly endless mountain range, which stretches to the horizon. As sunset approaches, the mountains cast longer shadows, which slowly cover ...

1 October 2012: This impressive panoramic image depicts the Chajnantor Plateau — home of the Atacama Large Millimeter/submillimeter Array (ALMA) — with the majestic Licancabur volcano in the background. Watched over by Licancabur, a icy forest of penitentes (Spanish for “penitents”) cluster in the foreground. The penitentes are a curious natural phenomenon found in high-altitude regions. They are thin spikes of hardened snow or ice, with sharp edges pointing towards the Sun, reaching heights from a few centimetres up to several metres. You can read more about penitentes in a previous Picture of the Week (potw1221). The Licancabur volcano, with an altitude of 5920 metres, is the most iconic volcano in the area of San Pedro de Atacama, Chile. Its conical shape makes it easily recognisable even from very far away. It is located on the southernmost part of the border between Chile and Bolivia. The volcano contains one of the world’s highest ...

24 September 2012: Sunset is typically a sign that another working day is over. City lights are slowly switched on as people return home eager to enjoy the evening and a good night’s sleep. However, this does not apply to astronomers working at an observatory such as ESO’s Paranal Observatory in Chile. Observing starts as soon as the Sun has disappeared below the horizon. Everything needs to be ready before dusk. This panoramic photograph captures the ESO Very Large Telescope (VLT) against a beautiful twilight on Cerro Paranal. The enclosures of the VLT stand out in the picture as the telescopes in them are readied for a night of studying the Universe. The VLT is the world’s most powerful advanced optical telescope, consisting of four Unit Telescopes with primary mirrors 8.2 metres in diameter and four movable 1.8-metre Auxiliary Telescopes (ATs), which can be seen in the left corner of the image. The ...

17 September 2012: A crystal-clear sky on any night is always a joy to behold. But if you are on the Chajnantor Plateau, at 5000 metres altitude in the Chilean Andes and one of the best places in the world for astronomical observations, it could be an experience that you’ll remember for your whole life. This panoramic view of Chajnantor shows the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) against a breathtaking starry night sky. In the foreground, we can see some of ALMA’s antennas, working together. The plateau appears curved, because of the effect of the wide-angle lens used. ALMA is the world’s most powerful telescope for studying the Universe at submillimetre and millimetre wavelengths. Construction work for ALMA will be completed in 2013, and a total of 66 of these high-precision antennas will be operating on the site. At the moment, the telescope is in its initial phase of Early ...

10 September 2012: ESO turns fifty this year, and to celebrate this important anniversary, we are showing you glimpses into our history. Once a month during 2012, a special Then and Now comparison Picture of the Week shows how things have changed over the decades at the La Silla and Paranal Observatory sites, the ESO facilities in Santiago de Chile, and the Headquarters in Garching bei München, Germany. This month, we are showing a part of ESO that feels almost timeless. After a long intercontinental flight to Santiago, or the night-shifts of an observing run at the telescopes, what could be better than a comfortable staging post at which to recover and rest before the next part of the journey? From the organisation’s earliest years, ESO’s Guesthouse in Santiago has provided just this for visitors to the observatory’s sites in Chile. Our Then and Now photographs this month show the guesthouse lounge, in ...

3 September 2012: This colourful new view shows the star-forming region LHA 120-N44 [1] in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way. This picture combines the view in visible light from the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile with images in infrared light and X-rays from orbiting satellite observatories. At the centre of this very rich region of gas, dust and young stars lies the star cluster NGC 1929. Its massive stars produce intense radiation, expel matter at high speeds as stellar winds, and race through their short but brilliant lives to explode as supernovae. The winds and supernova shock waves have carved out a huge cavity, called a superbubble, in the surrounding gas. Observations with NASA's Chandra X-ray Observatory (shown here in blue) reveal hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (shown in red) ...

27 August 2012: Imagine that you have just watched a beautiful sunset from the top of Cerro Paranal. As the Atacama Desert silently fades into the night, ESO’s Very Large Telescope (VLT) opens its powerful eyes on the Universe. With this spectacular 360-degree panorama, you can imagine the view that you would have if you were standing there, near the southern edge of the VLT’s platform. In the foreground, the fourth of the VLT’s Auxiliary Telescopes (AT4) is opening. To its left, the Sun has already set over the Pacific Ocean — covered by clouds below the altitude of Paranal, as usual. Across the rest of the platform, the other three Auxiliary Telescopes are seen in front of the large buildings of the four 8.2-metre Unit Telescopes. Finally, the Residencia and other basecamp facilities are also visible a little distance away, near the right-hand edge of the picture. As the night begins, imagine ...

20 August 2012: A powerful laser beam from ESO’s Very Large Telescope (VLT) paints the night sky over the Chilean Atacama Desert in this stunning image taken by Julien Girard. The Earth’s rotation during the 30-minute exposure — and the movement of the laser as it compensated for this — is why the beam appears to fan out. This is also why the stars are stretched into curved trails, revealing subtle differences in their colours. The laser is used to create a point of light — an artificial star — by making sodium atoms 90 kilometres up in the Earth’s atmosphere glow. Measurements of this so-called guide star are used to correct for the blurring effect of the atmosphere in astronomical observations — a technique known as adaptive optics. While sufficiently bright natural stars are also used for adaptive optics, a laser guide star can be positioned wherever it is needed, meaning that ...