Fotografia da Semana

2 de Fevereiro de 2009: O par de galáxias NGC 1531/2, envolvido numa valsa animada, está a uma distância de cerca de 70 milhões de anos-luz, na direção da constelação austral do Erídano. Em primeiro plano vemos NGC 1532, uma galáxia em espiral deformada com faixas de poeira, cuja distorção se deve à sua proximidade com a sua companheira, uma galáxia com núcleo brilhante (NGC 1531), visível em plano de fundo, por cima do centro da NGC 1532. Consequentemente, um dos braços em espiral da NGC 1532 está torcido e podemos observar nuvens de poeira e gás por cima do seu disco. Além disso, esta dança cósmica dá ainda origem a outro fenómeno: o nascimento de uma nova geração de estrelas na NGC 1532, visíveis como objetos roxos nos braços em espiral. Esta imagem foi obtida com o auxílio do telescópio dinamarquês de 1,5 metros no Observatório de La Silla do ESO, no Chile, e ...

26 de Janeiro de 2009: The 8.2m diameter main mirror of Antu, the first Unit Telescope of ESO's Very Large Telescope, is being cleaned using carbon dioxide snow. While the telescope enclosure is maintained extremely clean, the mirrors are exposed to the elements during the observations. Consequently, dust from the desert slowly accumulates over the surface of the mirror, making it less reflective over time. The mirror's surface is so delicate that normal cleaners used for household mirrors are not appropriate for telescopes. Observatories have developed other methods, such as this one using carbon dioxide snow. The tiny CO2 snowflakes in the white plume have a temperature of almost minus 80 degrees Celsius; when they land on the mirror, which is at room temperature, they cause minuscule 'explosions' that detach the dust grains from the surface. The dust then floats away, leaving the mirror clean. The process is nevertheless very delicate: should Alain Gilliotte, the ...

12 de Janeiro de 2009: The Orion Nebula is arguably the finest of all nebulae within the Milky Way visible from the Northern Hemisphere. With a gaseous repository of 10,000 suns, and illuminated by a cluster of hot young stars, the clouds of Messier 42 — as it is also known — glow with fantastic colours and shapes, giving us a bird’s eye view of one of the greatest star forming nurseries in our part of the Milky Way. Messier 42 is a complex of glowing gas, mostly hydrogen but also helium, carbon, nitrogen, and oxygen in decreasing amounts, located 1,500 light-years away. At its very heart, we find the Trapezium, a group of four very hot stars that illuminate the nebula. They are the brightest of an extended cluster of several thousand young stars many of which lie unseen within the opaque gas and dust. Amazingly, whilst the Orion Nebula is easy to identify ...

15 de Dezembro de 2008: The striking, large spiral galaxy NGC 1232, and its distorted companion shaped like the greek letter "theta". The pair is located roughly 60 million light-years away in the constellation Eridanus (The River). Billions of stars and dark dust are caught up in this beautiful gravitational swirl. The blue spiral arms with their many young stars and star-forming regions make a striking contrast with the yellow-reddish core of older stars. This image is based on data acquired with the 1.5 m Danish telescope at the ESO La Silla Observatory in Chile, through three filters (B: 900 s, V: 400 s, R: 400 s).

8 de Dezembro de 2008: About a year ago, ESO kindly agreed to donate a surplus van to the Colegio Hellen Keller, a school for children with visual disabilities, located in Santiago, Chile. The school was in desperate need of some form of transport as there were many children who could either not attend school at all, or had to spend the weekdays away from their family, simply because they could not make the daily journey on public transport, due to their disabilities. The initial idea was to donate one of the bus used to carry staff to Paranal. However, it became clear that this big van was not ideal for the school, especially with rising fuel prices. ESO kindly offered to donate the proceeds from the sale of the van instead, which was in excess of 4.000.000 Chilean Pesos (about 5,000 EUR). The school set up a fund to raise the rest of the ...

1 de Dezembro de 2008: Supernova 2008bk in the spiral galaxy NGC 7793 was discovered at the end of March 2008 by amateur astronomer Berto Monard from South Africa. The galaxy is 13 million light-years away in the direction of Sculptor constellation. This supernova is a typical example of a massive star that exploded at the end of its life. But this time, the astronomers were able not only to see the explosion, but to precisely pinpoint the star that exploded, a rather rare achievement. This was made possible because the explosion site had been observed several times with the help of ESO's Very Large Telescope, the latest images having been observed only a few months before the explosion with the new HAWK-I instrument. An European team of astronomers, led by Seppo Mattila of University of Turku, Finland, then observed the explosion site again two months after the supernova's discovery, this time with the VLT's ...

25 de Novembro de 2008: O Very Large Telescope (VLT) a 2600 metros de altitude no Cerro Paranal é o principal local do ESO onde se fazem observações no visível e no infravermelho. Está localizado no deserto chileno do Atacama. Os quatro telescópios de 8,2 metros de diâmetro estão a operar individualmente, tendo ao seu dispor uma enorme colecção de instrumentos, e fizeram já importantes descobertas científicas.O VLT oferece também a possibilidade de combinar a luz dos quatro telescópios principais de forma coerente, trabalhando assim como um interferómetro. O Interferómetro do Very Large Telescope (VLTI), com o seu equipamento próprio, pode obter imagens com a precisão do milisegundo de arco e astrometria com 10 microsegundos de arco de precisão. Para além dos telescópios de 8,2 metros, o VLTI é complementado por quatro telescópios auxiliares (AT) de 1,8 metros de diâmetro cada um, que melhoram as suas capacidades de imagem e permitem utilizar o VLTI durante ...

11 de Novembro de 2008: The Carina Nebula is a large bright nebula that surrounds several clusters of stars. It contains two of the most massive and luminous stars in our Milky Way galaxy, Eta Carinae and HD 93129A. Located 7500 light years away, the nebula itself spans some 260 light years across, about 7 times the size of the Orion Nebula, and is shown in all its glory in this mosaic. It is based on images collected with the 1.5-m Danish telescope at ESO's La Silla Observatory. Being brighter than one million Suns, Eta Carinae (the brightest star in this image) is the most luminous star known in the Galaxy, and has most likely a mass over 100 times that of the Sun. It is the closest example of a luminous blue variable, the last phase in the life of a very massive star before it explodes in a fiery supernova. Eta Carinae is ...

4 de Novembro de 2008: M1-67 is the youngest wind-nebula around a Wolf-Rayet star, called WR124, in our Galaxy. These Wolf-Rayet stars start their lives with dozens of times the mass of our Sun, but loose most of it through a powerful wind, which is ultimately responsible for the formation of the nebula. Ten years ago, Hubble Space Telescope observations revealed a wealth of small knots and substructures inside the nebula. The same team, led by Cédric Foellmi (ESO), has now used ESO's Very Large Telescope (VLT) to watch how these structures have evolved and what they can teach us about stellar winds, their chemistry, and how they mix with the surrounding interstellar medium, before the star will eventually blow everything away in a fiery supernova explosion. The image is based on FORS1 data obtained by the Paranal Science team with the VLT through 2 wide (B and V) and 3 narrow-band filters.

30 de Setembro de 2008: A night of work for the Paranal Observatory, in the Chilean Atacama Desert. This picture, taken on 20 September, shows the incredible beauty of the night sky above the most advanced telescope in the world, ESO's Very Large Telescope. The Milky Way is clearly seen in this superb image.

22 de Setembro de 2008: Composite colour-coded image of another magnificent spiral galaxy, NGC 7424, at a distance of 40 million light-years. It is based on images obtained with the multi-mode VIMOS instrument on the ESO Very Large Telescope (VLT) in three different wavelength bands. The image covers 6.5 x 7.2 square arcminutes on the sky. North is up and East is to the right. Read more about this superb object in the ESO Press Release eso0436.

21 de Agosto de 2008: Imagem composta a cores do enxame globular NGC 3201, obtida pelo instrumento WFI montado no telescópio ESO/MPG de 2,2 metros, em La Silla. Os enxames globulares são enormes agregados de estrelas, que podem conter milhões de estrelas. Encontram-se entre os objetos mais velhos observados no Universo, tendo-se formado presumivelmente ao mesmo tempo que a Via Láctea, durante a fase inicial posterior ao Big Bang. Este enxame globular em particular situa-se a cerca de 16000 anos-luz de distância na direção da constelação austral da Vela. Os dados obtidos fazem parte do rastreio EIS (ESO Imaging Survey), um rastreio público levado a cabo pelo ESO e pelos Estados Membros, em preparação para a primeira luz do VLT.A imagem original e os dados astronómicos podem ser obtidos através das páginas EIS Pre-Flames Survey Data Release, onde se encontram igualmente disponíveis muitas outras imagens.

14 de Agosto de 2008: The centre of our Milky Way galaxy is located in the southern constellation Sagittarius (The Archer) and is "only" 26,000 light-years away. On high-resolution images, it is possible to discern thousands of individual stars within the central, one light-year wide region. Using the motions of these stars to probe the gravitational field, observations over the last decade have shown that a mass of about 3 million times that of the Sun is concentrated within a radius of only 10 light-days of the compact radio and X-ray source SgrA* (Sagittarius A) at the centre of the star cluster. This means that SgrA* is the most likely counterpart of the black hole believed to exist at the centre of our Galaxy. This image was obtained in mid-2002 with the NACO instrument at the 8.2-m VLT Yepun telescope. It combines frames in three infrared wavebands between 1.6 and 3.5 µm. The compact objects ...

7 de Agosto de 2008: Paranal, the site of the VLT, was chosen for its unique characteristics: extreme dryness, very low cloud coverage, high altitude, and distant from any source of pollution. This wide-angle shot of the Atacama desert around Paranal, which shows the VLT and, in foreground, VISTA, summarizes it all. Photo taken in November 2007.

30 de Julho de 2008: The "Very Large Telescope Video Collection 2008" features High Definition video material which was obtained in June 2008. For the first time, ESO distributes HD-footage of the world's most advanced ground-based observing facility and provides free access to video sequences of outstanding technical quality and beauty. The material has been edited especially for broadcast use, without commentary or music.

17 de Julho de 2008: The first successful movement of an ALMA antenna took place at the Operations Support Facility (OSF) on 8 July 2008. The antenna transporter "Lore", one of the two units manufactured by Scheuerle under contract by ESO and delivered recently at the OSF, has been used to move one 12-m antenna from their site erection facility to an external antenna pad for sky testing.

7 de Julho de 2008: Enquanto o ALMA está a ser construído, os astrónomos fazem já astronomia milimétrica e submilimétrica no Chajnantor com o auxílio do Atacama Pathfinder Experiment (APEX). Trata-se de um telescópio de alta tecnologia de 12 metros, baseado numa antena protótipo do ALMA, que opera no local do ALMA. O telescópio, que dispõe de óptica modificada e de uma superfície de antena melhorada, foi concebido para tirar partido da excelente transparência do céu e opera na região de comprimentos de onda compreendida entre 0,2 e 1,4 mm.

1 de Julho de 2008: The image shows X-shooter, the first of the second generation VLT instruments, under test in the integration lab at ESO, Garching. The instrument has been built by a Consortium including ESO and institutes from Denmark, Italy, The Netherlands and France, and will start operation at the telescope in 2009. X-shooter is a single target, wide band, intermediate spectral resolution spectrograph, designed to get the full spectrum of the faintest cosmic sources from the atmospheric cutoff in the near-ultraviolet to the infrared K-band in a single exposure. In this image the instrument is shown as mounted on a telescope Cassegrain focus simulator, pointing at a large zenith distance. At the centre is the cryostat with the near-infrared arm of the spectrograph and at the left is the lower side of the visual spectrograph with its CCD detector. The two large boxes on the sides host the control electronics of the instrument.

23 de Junho de 2008: The winding road connecting the ALMA Operation Support Facility at 3,000m altitude to the Array Operation Site (5,000m high) passes an area between 3500m and 3800m dominated by large cacti (Echinopsis Atacamensis). These cacti grow on average 1cm per year, and reach heights of up to 9m. Stephane Guisard recently captured the beautiful sky above this unique location in the Chilean Atacama Desert. The Milky Way is seen in all its glory, as well as, in the lower right, the Large Magellanic Cloud.

10 de Junho de 2008: This aerial view of Cerro Paranal, the site of ESO's Very Large Telescope, was obtained in 1994. It shows the construction of the concrete base for the four telescope enclosures. To the left and a little lower than the rest of the platform is the excavation for the control building. The platform altitude is about 2640 metres above sea level and it measures about 150 metres across. The width of the access road is no less than 12 metres, i.e. nearly equal to that of a three-lane highway; this is necessary to ensure the safe transport of all telescope parts, especially the four 8.2-metre fragile mirrors, to the top. The summit of Paranal has been blasted away so to create the flat platform that supports the 4 Unit Telescopes, as well as the network of tunnels that transport the light from the telescopes to the interferometric laboratory. On this 1994 ...