Lehdistötiedotteet

23. tammikuuta 1998: We show here five high-resolution photographic images (4-6 Mbytes) from the ESO Paranal Observatory, the site of ESO's Very Large Telescope Array (VLT).

22. tammikuuta 1998: This spring, teachers across Europe will enjoy support for exciting, novel educational projects on astronomy, navigation and environmental observations. The largely web-based and highly interactive SEA & SPACE programme makes it possible for pupils to perform field experiments and astronomical observations and to obtain and process satellite images. A contest will take the best pupils for one week to Lisbon (Portugal), to Europe's space port in Kourou (French Guyana) where the European launcher lifts off or to ESO's Very Large Telescope at the Cerro Paranal Observatory in Chile, the largest optical telescope in the world.

16. tammikuuta 1998: We continue the publication of video clips from the Paranal Observatory by showing aerial scenes of the VLT site and an overall view of Unit Telescope 1 in its enclosure. The footage was obtained by the ESO EPR Video Team during a recent mission.

13. tammikuuta 1998: Within a few months, the first 8.2-meter Unit Telescope of the ESO Very Large Telescope (VLT) array will open its eye towards the sky above the Atacama desert. As documented by recent Press Photos from ESO, the construction work at the Paranal VLT Observatory is proceeding rapidly. Virtually all of the telescope components, including the giant Zerodur mirror, are now on the mountain.

22. joulukuuta 1997: We publish here as first examples three clips from the transport of the first VLT 8.2-m Zerodur mirror (M1) from the port of Antofagasta to the Paranal Observatory, as obtained by the ESO EPR Video Team.

19. joulukuuta 1997: The present collection of twelve high-resolution photographic images illustrates the transport of the first VLT 8.2-m Zerodur mirror (M1) to Paranal. They are suitable for high-quality reproduction and complement the digital, less detailed ESO Press Photos 33a-f/97 which were published one week ago with information about this important event.

12. joulukuuta 1997: Just as the first 8.2-metre Zerodur VLT primary mirror (M1) is arriving at the Paranal Observatory, there are also good news about the first of the 1.2-m Beryllium VLT secondary mirrors (M2) and its Supporting Unit . This assembly is placed at the top of the VLT 'telescope tube'.

12. joulukuuta 1997: Another historic event in ESO's Very Large Telescope Project has just occurred. The first giant mirror is on the mountain! The blanks for the four 8.2-metre VLT mirrors of Zerodur were produced by the Schott Glaswerke (Mainz, Germany) and have been polished at the REOSC factory (St. Pierre du Perray, France). For more information, see ESO Press Release 15/95. The first of the four mirrors left France in early November 1997 en route to Paranal. The transport was organized by the Gondrand company.

2. joulukuuta 1997: The main structure of the ESO Very Large Telescope (VLT) has been designed, produced and assembled by an Italian consortium composed of Ansaldo Energia (Genova), European Industrial Engineering (Venice) and SOIMI (Milan). A total of four identical structures have been built, one for each of the four VLT 8.2-m Unit Telescopes.

24. marraskuuta 1997: When is a minor object in the solar system a comet? And when is it an asteroid? Until recently, there was little doubt. Any object that was found to display a tail or appeared diffuse was a comet of ice and dust grains, and any that didn't, was an asteroid of solid rock. Moreover, comets normally move in rather elongated orbits, while most asteroids follow near-circular orbits close to the main plane of the solar system in which the major planets move.

17. marraskuuta 1997: After a long journey from Europe, the first Very Large Telescope mirror cell (VLT M1 cell) and a concrete 8.2-m dummy mirror were unloaded in the Port of Antofagasta on October 31, 1997. From here, they were transported by special trucks to the Paranal Observatory.

22. lokakuuta 1997: During the past month, there has been much action in many different areas at the ESO Paranal Observatory. Work has continued on the assembly of various components of the telescope structures and on the surface of the summit platform, as well as in connection with the maintenance and storage facilities near the base camp at the foot of the mountain.

8. lokakuuta 1997: After having passed behind the Sun (as seen from the Earth), Comet Hale-Bopp is now again well visible to observers in the southern sky. Although this famous object is now three times farther away than when it passed its closest point to the Sun (the perihelion) on April 1, 1997, it is still quite bright, especially when compared to other comets that have been observed at the same distance. Its magnitude is now around 5, i.e. when seen in a dark sky it is just visible with the unaided eye. However, it is seen better through moderate-size binoculars and is of course still more interesting when observed with a large, professional telescope.

22. syyskuuta 1997: With the completed assembly of the heavy parts that form the mechanical structure of the first (UT1) of the four large VLT Unit Telescopes, the integration of the motor that will move the telescope around the (horizontal) altitude axis is now about to start.

10. syyskuuta 1997: In this continuing series of views from the ESO Paranal Observatory, most have been related to developments around the VLT telescopes and their enclosures. While this assembly work is very important and now rapidly progresses towards the crucial moment of First Light, other activities are also going on which will ensure the proper functioning of the small, isolated community at Paranal, in the middle of the extreme Atacama desert.

29. elokuuta 1997: Here are some recent photos from the installation of the ESO Very Large Telescope (VLT) at the Paranal Observatory in Northern Chile.

12. elokuuta 1997: One more important step within the ESO Very Large Telescope (VLT) project has just been successfully accomplished. After a journey of more than 12,000 km, the enormous coating plant for the 8.2-m VLT Zerodur mirrors has just arrived safely at the Paranal Observatory in the Atacama desert. Here it is now being installed in the Mirror Maintenance Building (MMB) , a large and complex structure that has been constructed next to the base camp, at the foot of the Paranal mountain.

8. elokuuta 1997: The installation of the ESO Very Large Telescope (VLT) at the Paranal Observatory in the Chilean Atacama desert continues at good pace. As the moment of first light of the first 8.2-metre telescope is getting closer, the assembly of the enormous, 400-ton mechanical structure proceeds according to schedule.

1. elokuuta 1997: Observations of the bright southern quasar HE 2347-4342 with telescopes at the ESO La Silla Observatory and with the NASA/ESA Hubble Space Telescope (HST) have provided a group of European astronomers [1] with an exceptional glimpse into an early, still unexplored transition period of the Universe.

25. heinäkuuta 1997: About 20 cases of gravitationally lensed (GL) quasars are known. This special physical effect, also known as a cosmic mirage, occurs when the rays of light of a distant quasar on their way to us pass near a massive object, for instance a galaxy. As a result, two or more images of the same quasar will be seen near each other. This phenomenon is described in more detail in the Appendix. A new study by a group of three European astronomers, headed by Frederic Courbin ( Institut d'Astrophysique, Universite de Liege, Belgium, and Observatoire de Paris-Meudon, France) [1], has led to the discovery of the object responsible for the double images of a remote quasar in the gravitational lens HE 1104-1805 . The investigation is based on infrared observations at the ESO La Silla Observatory in Chile and the `lensing system' turns out to be a distant, massive galaxy. Nevertheless, the geometry of the object is unusual and an additional gravitational lens of `dark' (invisible) matter may possibly be involved.

22. heinäkuuta 1997: In the course of the major observational programme of asteroids by the Institute of Planetary Exploration of the German Aerospace Research Establishment (DLR) [1] in Berlin, two of the staff astronomers, Stefano Mottola and Gerhard Hahn, have discovered a small satellite (moon) orbiting the asteroid (3671) Dionysus.

17. heinäkuuta 1997: ESO Press Photo eso9717a shows a recent aerial view of the modernistic building of the ESO Headquarters in the town of Garching, some 15 kilometres north of Munich, the capital of Bavaria, Germany.

17. heinäkuuta 1997: The following seven photos are part of an extensive series that was obtained in mid-June 1997. The first three are aerial views which demonstrate the good progress of the extensive work at the top of the mountain where the four large enclosures for the ESO Very Large Telescope (VLT) 8.2-metre Unit Telescopes, the interferometric tunnel system and the control building are now steadily approaching completion.

17. kesäkuuta 1997: On this photo, two major astronomical instruments equipped with state of the art infrared array detectors are seen undergoing final integration and testing at the Assembly Laboratory at the ESO Headquarters (Garching, Germany) prior to being shipped to the ESO observatories in Chile. It was obtained a few days after a visit to this laboratory by the ESO Council at the time of its June 1997 meeting in Garching.

11. kesäkuuta 1997: This new and very detailed image of the famous circumstellar disk around the southern star Beta Pictoris was obtained with the ESO ADONIS adaptive optics system at the 3.6-m telescope and the Observatoire de Grenoble coronograph. It shows (in false colours) the scattered light at wavelength 1.25 micron (J band) and is one of the best images of this interesting feature obtained so far.

2. kesäkuuta 1997: Hans Hermann Heyer, professional ESO photographer at the Education and Public Relations Department in Garching, has prepared a remarkable exhibition of 45 photographs he obtained during two visits to ESO-Chile in 1996. It is on display at the ESO Headquarters until July 10, 1997.

2. kesäkuuta 1997: The installation of the ESO Very Large Telescope at the Paranal Observatory in the Chilean Atacama desert is proceeding rapidly. The moment of first light of the first 8.2-metre telescope is getting closer and activities in Paranal and at the ESO Headquarters in Garching are becoming ever more intense.

16. toukokuuta 1997: In August 1995, the European Southern Observatory signed a contract with Linde A.G. (Germany), for the supply of the coating unit for the giant mirrors of the ESO Very Large Telescope (VLT). Together with the main subcontractors, BOC coating technology (UK) , and Deggendorfer Werft (Germany), Linde has meanwhile completed the development, construction and pre-commissioning of the coating unit in Deggendorf, a town located at the Danube River, some 150 km northeast of Munich.

12. toukokuuta 1997: ESO Messenger no. 87 (March 1997) contains information (on Page 5) about the content of the Time Capsule, deposited by President Frei of the Republic of Chile on December 4, 1996, in the wall of VLT Enclosure no. 1. This capsule, an aluminium cylinder of 15 cm diameter and 45 centimeter long, was filled with nitrogen gas and sealed hermetically. A commemorative plaque was fixed in front of the cavity. In addition to the various items listed below, the capsule also contains a list of contents etched on a metal plate which will survive virtually indefinitely in this environment, while it cannot be excluded that the papers may deteriorate with time.

28. huhtikuuta 1997: Brown Dwarfs are star-like objects which are too small to become real stars, yet too large to be real planets. Their mass is too small to ignite those nuclear processes which are responsible for the large energies and high temperatures of stars, but it is much larger than that of the planets we know in our solar system. Until now, very few Brown Dwarfs have been securely identified as such. Two are members of double-star systems, and a few more are located deep within the Pleiades star cluster. Now, however, Maria Teresa Ruiz of the Astronomy Department at Universidad de Chile (Santiago de Chile), using telescopes at the ESO La Silla observatory, has just discovered one that is all alone and apparently quite near to us. Contrary to the others which are influenced by other objects in their immediate surroundings, this new Brown Dwarf is unaffected and will thus be a perfect object for further investigations that may finally allow us to better understand these very interesting celestial bodies. It has been suggested that Brown Dwarfs may constitute a substantial part of the unseen dark matter in our Galaxy. This discovery may therefore also have important implications for this highly relevant research area.

9. huhtikuuta 1997: Circumstellar disks of gas and dust play a crucial role in the formation of stars and planets. Until now, high-resolution images of such disks around young stars within the Orion Nebula obtained with the Hubble Space Telescope (HST) constituted the most direct proof of their existence. Now, another circumstellar disk has been detected around a star in the Lagoon Nebula - also known as Messier 8 (M8) , a giant complex of interstellar gas and dust with many young stars in the southern constellation of Sagittarius and four times more distant than the Orion Nebula. The observations were carried out by an international team of scientists led by Bringfried Stecklum (Thüringer Landessternwarte, Tautenburg, Germany) [1] who used telescopes located at the ESO La Silla observatory and also observations from the HST archive. These new results are paving the road towards exciting research programmes on star formation which will become possible with the ESO Very Large Telescope.

20. maaliskuuta 1997: These photos show one of the three generating sets (08a/97 and 08b/97) that will constitute the electric power station of the ESO Paranal Observatory of the Very Large Telescope Observatory (VLT).

11. maaliskuuta 1997: An international team of astronomers has used large telescopes in Chile and Australia to measure the biggest star in the sky. The star, designated R Doradus , is of the so-called red giant type and is located in the southern constellation of Dorado. Its apparent diameter (i.e., the size which the star appears to have when seen from the Earth) is larger than any other so far observed, except for the Sun. In particular, it exceeds by more than 30% that of Betelgeuse , which for the past 75 years has held the title of star with the largest apparent size.

5. maaliskuuta 1997: In the afternoon of March 9, 1997, the Bavarian Prime Minister, Dr. Edmund Stoiber, on the invitation of the Director General of ESO, Professor Riccardo Giacconi, visited the ESO La Silla Observatory, located in an isolated area in the Atacama desert some 600 km north of the Chilean capital.

28. helmikuuta 1997: This week astronomers at the European Southern Observatory have tested a novel approach of doing astronomy from the ground. Inaugurating a new era, the ESO 3.5-metre New Technology Telescope (NTT) at La Silla successfully performed a series of observations under automatic control by advanced computer software developed by the ESO Data Management Division (DMD) for use with the ESO Very Large Telescope (VLT). This move has been made necessary by technological improvements in telescopes and the increasing competition among scientists for these valuable resources.

15. tammikuuta 1997: Recent observations with the Hubble Space Telescope (HST) have documented an unexpected and rapid, seven-fold brightening of an unusual double star at the centre of the impressive 47 Tucanae globular cluster in the southern sky. This is the first HST observation of such a rare phenomenon. The astronomers [1] who are involved in this observational program find that this event cannot be explained by any of the common processes known to occur in such stars.

14. tammikuuta 1997: The following success story is a classical illustration of scientific progress through concerted interplay of observation and theory. It concerns a 35-year old mystery which has now been solved by means of exciting observations of a strange double star. An added touch is the successive involvement of astronomers connected to the European Southern Observatory.

9. tammikuuta 1997: This impressive nocturnal image of Cerro Paranal, the site of the ESO VLT Observatory, inaugurates the series of ESO Press Photos in 1997, a decisive year for the Very Large Telescope Project. Only one year now remains until first light will be obtained with the first of the giant 8.2-metre telescopes in the VLT array. Recent daytime aerial photos of Paranal are available as ESO Press Photos 40a+b/96.

23. joulukuuta 1996: This series of four images shows the appearance of Comet Hale Bopp in early November 1996. At this time it was approaching the Sun in the sky, and these images are some of the last made by a major astronomical telescope in 1996. They were made by Hermann Boehnhardt of the Astronomical Institute of the Ludwig-Maximilian-University in Munich (Germany).

23. joulukuuta 1996: These aerial photos, obtained on December 8, 1996, show the rapid construction progress at the site of the VLT Observatory on Cerro Paranal.

28. marraskuuta 1996: According to the widely accepted Big Bang theory, the first galaxies formed by gravitational accretion from slight irregularities in a primordial sea of matter, a process that required considerable time. Hence it would be expected that there would be a delay between the Big Bang and the appearance of the first galaxies. Or, looking back in time from the present, we would expect to find an epoch in the distant past when galaxies had not yet come into being.

13. marraskuuta 1996: The Astronomy On-line Programme began officially on 1 October and is now about to enter its most intense phase, known as the Hot Week . On 18 - 22 November, an estimated 4000 astronomy-interested, mostly young people in Europe and on four other continents will get together during five days in what - not unexpected - has become the world's biggest astronomy event ever organised on the World Wide Web.

28. lokakuuta 1996: The construction of the largest optical telescope in the world, the ESO Very Large Telescope (VLT) , continues at full speed, aiming at first-light towards the end of 1997. There is hectic activity on all fronts, both at the Paranal Observatory in Chile and at the many involved industrial firms in Europe.

20. syyskuuta 1996: This heavily processed image of C/1995 O1 (Hale-Bopp) is based on a CCD frame that was obtained on August 18, 1996, by Nick Thomas (Max-Planck-Institut fuer Aeronomie, Germany) and Heike Rauer (Observatoire de Paris, France), observing with the DFOSC multi-mode instrument on the Danish 1.54-m telescope at La Silla. The frame was taken at 04:20 UT through an R filter (to show the dust around the cometary nucleus) and the integration time was 20 s.

16. syyskuuta 1996: On August 7, 1996, Eric W. Elst (Royal Observatory, Uccle, Belgium) reported his discovery of a cometary image on mid-July exposures by Guido Pizarro with the 1.0-m ESO Schmidt telescope at the La Silla Observatory. Further ESO Schmidt plates were then obtained, and on August 19, with the help of orbital computations by Brian Marsden (IAU Central Bureau for Astronomical Telegrams, Cambridge, Mass., USA), Elst was able to identify the object on them. Even though the orbit (Period = 5.6 years; inclination = 1.4 deg; eccentricity = 0.17) is entirely characteristic of that of a main-belt minor planet with the implied long-term orbital stability, the continued presence of a tail seemingly confirms the object as a 'comet'. The object now carries the designation 'Comet P/1996 N2 (Elst-Pizarro)'.

5. syyskuuta 1996: On 5 September 1996, the Senate of the Republic of Chile (Second Chamber of the Parliament) has ratified the Interpretative, Supplementary and Modifying Agreement to the Convention of 1963, which regulates the relations between the European Southern Observatory and its host country, the Republic of Chile.

14. elokuuta 1996: ISAAC (Infrared Spectrograph And Array Camera) will be the first major instrument to be installed at VLT Unit Telescope no. 1; according to the current planning, this will happen by mid-1998. ESO Press Photo eso9635a shows this complex instrument during the present, thorough technical tests in the Infrared Laboratory at the ESO Headquarters in Garching (Germany).

2. elokuuta 1996: The past four centuries have seen dramatic improvements in astronomical equipment, in terms of better and larger telescopes, more accurate and sensitive detectors and, not the least, by advanced space instruments with access to new spectral regions. However, until recently there has been little progress on another equally important front, that of quantifying the unavoidable influence of this equipment on the astronomical data they produce. For a long time, astronomers have desired to remove efficiently these `instrumental effects' from their data, in order to give them a clearer understanding of the objects in the Universe and their properties. But it is only now that this fundamental problem can finally be tackled efficiently, with the advent of digital imaging techniques and powerful computers.

1. elokuuta 1996: The Local Group of Galaxies consists of a few large spiral galaxies - for instance the Milky Way galaxy in which we live, and the Andromeda galaxy that is visible to the unaided eye in the northern constellation of the same name - as well as two dozen much smaller galaxies of mostly irregular shape. Whereas the larger galaxies have extended halos of very old stars, no such halos have ever been seen around the smaller ones. Now, however, Dante Minniti and Albert Zijlstra [1], working at the ESO 3.5-metre New Technology Telescope (NTT), have found a large halo of old and metal-poor stars around one of the dwarf galaxies in the Local Group. This finding is quite unexpected. It revises our understanding of star formation in these galaxies and provides important information about the past evolution of galaxies [2].

25. heinäkuuta 1996: Each of the giant Zerodur mirrors for the four unit telescopes of the ESO Very Large Telescope (VLT) , with a diameter of 8.2-metres and a total area of more than 50 square metres, will be supported by a complex steel structure, referred to as the M1 Cell . This structure will also support the M3 Tower that protrudes from the central hole of the mirror and carries a flat mirror (M3) that serves to reflect the light towards the Nasmyth platforms on either side of the telescope. On these platforms are placed the heavy instruments that will record the light from celestial objects collected by the telescope.

25. heinäkuuta 1996: Using telescopes in Chile, Europe, Australia and the USA, an international team of astronomers [1] has discovered large empty regions ('holes') in what they refer to as the 'local Universe'. These regions, as well as others with excess mass density are revealed by a study of the motions in space of more than 2000 galaxies. They are among the largest structures ever seen in the Universe and have diameters of up to 100 million light years.

18. kesäkuuta 1996: Astronomy On-Line is a major, all-European project that will take place in conjunction with the 4th European Week for Scientific and Technological Culture later this year. It is based on intensive use of the World-Wide-Web (WWW) and represents the first large-scale attempt in the world to bring together pupils and their teachers all over one continent to explore challenging scientific questions, using modern communication tools, both for obtaining and for communicating information.

30. toukokuuta 1996: The latest areal views showing the VLT building site at Cerro Paranal gives a good impression of the progress of the construction

24. toukokuuta 1996: The programme will be carried out in a collaboration between the European Association for Astronomy Education (EAAE) [1] and the European Southern Observatory, and together with the European Commission (EC).

20. toukokuuta 1996: Observations of Comet 1995 O1 (Hale-Bopp) continued at ESO during the period of May 10 - 14, 1996, with the MPI/ESO 2.2-m telescope and the multimode EFOSC II instrument. Both direct images and spectra were obtained.

20. toukokuuta 1996: The active phase of Astronomy On-Line will start on October 1 and reach a climax on November 18 - 22, 1996. A new and unknown comet was discovered by Robert Evans on a photographic plate, obtained by M. J. Drinkwater on May 10, 1996, with the UK Schmidt telescope at Siding Spring Australia. More observations were made within the next days and the comet was soon given the designation 'Comet 1996 J1' (i.e. the first comet to be found in the period May 1 - 15, 1996). Following astronomical tradition, it was also named after the discoverers.

18. huhtikuuta 1996: On April 12, two observers in Australia and Japan independently reported the sudden appearance of a supernova in the southern elliptical galaxy NGC 5061, a prominent object in the Centaurus constellation (IAUC 6380). The magnitude was about 13 (visual) and the exact position was measured as R.A. = 13h 18m 01.13s, Decl. = -26d 50m 45.3s (equinox 2000.0), or about 52 arcsec west and 31 arcsec south of the galaxy's center.

22. maaliskuuta 1996: A series of CCD frames, showing the inner coma of Comet Hale-Bopp, was obtained with the SUSI high angular resolution camera at the ESO 3.5-metre New Technology Telescope (NTT) under very good seeing conditions in the morning of March 20, 1996.

19. maaliskuuta 1996: The most recent ESO observations of bright Comet Hyakutake have shown rapid changes in the innermost coma, within a few hundred kilometres from the cometary nucleus. This result has only become possible because of the unusual combination of a bright comet being near the Earth, together with the excellent imaging quality of the ESO 3.5-metre New Technology Telescope (NTT).

17. maaliskuuta 1996: This new image obtained with ESO's New Technology Telescope (NTT) shows the circumnuclear region of the comet Hyakutake, expected to pass close to Earth in the upcoming days.

15. maaliskuuta 1996: Following recent observations at the ESO La Silla Observatory, there is now no doubt that Comet Hyakutake - as hoped - is developing into a major object! In any case, the observed, very complex structure as well as the extent of the tail system is typical of a bright and beautiful comet.

13. maaliskuuta 1996: A complete, optical spectrum of Comet Hyakutake was obtained with the ESO 1.52-m telescope (La Silla Observatory) by Hilmar Duerbeck (ESO) on UT March 8.3, 1996. For this observation, the Boller & Chivens spectrograph with a new UV-sensitive CCD chip was used. The subsequent data reduction was performed by the observer and Stefano Benetti (ESO) at ESO's office in Santiago de Chile.

7. maaliskuuta 1996: A bright 'new' star was discovered by Japanese amateur astronomer Yukio Sakurai in late February 1996. It is located in the star-rich, southern constellation of Sagittarius (The Archer) and qualifies to join an extremely select class of stars. In fact, we know only one additional object of this type and the remains of two - possibly three - others. Compared to the 6000 stars in the sky seen with the naked eye, the several millions so far catalogued, and the billions of stars photographed, it is a very special class indeed. Nevertheless, Sakurai's star holds unique information about a dramatic evolutionary state, which all stars must to pass through whose masses are more than a few times that of the Sun, but still too small to produce a supernova explosion. This happens just before they end their active life and cool down into visual oblivion.

6. maaliskuuta 1996: With the help of a new and more sensitive receiver, recently installed on the 15-metre Swedish-ESO Submillimetre Telescope (SEST) at the European Southern Observatory on the La Silla mountain in Chile, a team of European astronomers [1] has succeeded in discovering the first extra-galactic silicon-monoxide (SiO) maser . It is located in the atmosphere of the largest known star in the Large Magellanic Cloud, a satellite galaxy to the Milky Way. This observational feat now opens new, exciting possibilities for the study of individual stars in other galaxies in the Local Group. The continued search for extra-galactic SiO masers is a joint project of European and Australian astronomers, to be carried on with even more advanced instruments that will become available in the near future.

4. maaliskuuta 1996: This is the most detailed image so far obtained of the complex tail system of Comet Hyakutake. It was obtained with the ESO 1-m Schmidt telescope at La Silla on February 28.36 UT under good observing conditions by ESO night assistant Oscar Pizarro. The exposure lasted 60 min and was made on sensitized Kodak Pan 4415 film behind a GG385 filtre. This emulsion/filtre combination allows to record a broad spectral interval (3900-7000 A) whereby faint structures are better seen. However, detailed spectral information, by which the emitters may be identified, is lost for the same reason.

4. maaliskuuta 1996: Spectra of Comet Hyakutake were obtained at the ESO La Silla Observatory on February 29.3 UT by Klaus Simon (Institute for Astronomy and Astrophysics, University of Munich, Germany) and Chris Lidman (ESO-Chile). They used the Danish 1.54-m telescope with the multi-mode DFOSC instrument and a large CCD. The slit was centred on the brightest part of the cometary coma. The frames were reduced by S. Benetti (ESO-Chile).

2. maaliskuuta 1996: These false-colour images are reproductions from a short-exposure CCD frame, obtained with the Danish 1.54-metre telescope and the DFOSC instrument with a 2052 x 2052 pix Loral/Lesser CCD. They show the innermost coma of Comet Hyakutake and the pronounced asymmetry of the dust distribution around the nucleus.

21. helmikuuta 1996: During the first weeks following its discovery on January 31, 1996, Comet C/1996 B2 (Hyakutake) has gradually brightened from magnitude 11-12 to 8. As it moves nearer to the Sun and is headed for a close approach to the Earth in late March 1996, the observers continue to describe it as diffuse, with a central condensation, but no typical comet tails were seen so far.

16. helmikuuta 1996: In the early morning of January 31, 1996, Japanese amateur astronomer Yuji Hyakutake made his second comet discovery within five weeks. He found the new comet near the border between the southern constellations of Hydra (The Water-Snake) and Libra (The Scales), amazingly just three degrees from the position where he detected another comet on December 26, 1995.

16. helmikuuta 1996: This false-colour photo demonstrates the asymmetry, now apparent in the coma of Comet C/1996 B2 (Hyakutake). This comet will make a close approach to the Earth (15 million kilometres) on March 25, 1996.

11. helmikuuta 1996: This diagramme shows the first spectrum obtained of comet C/1996 B2 (Hyakutake), which is expected to pass near the Earth in late March 1996. It was taken by Tomaz Zwitter, visiting astronomer at the ESO La Silla Observatory from the University of Ljubljana, Slovenia. It has been flux- [(erg/s/cm2/A) within 2x14 arcsecond slit centered on comet] and wavelength- [Angstrom] calibrated.

11. helmikuuta 1996: These false-colour photos show the first images of comet C/1996 B2 (Hyakutake), obtained with the DFOSC instrument at the Danish 1.54-metre telescope at the ESO La Silla Observatory. This comet is expected to become quite bright when it passes near the Earth in late March 1996.

9. helmikuuta 1996: This false-colour image of Comet Hale-Bopp is the first to be obtained with a major astronomical telescope after the recent conjunction with the Sun. At the time of this observation, the comet was located in the southern constellation of Sagittarius, and only 32 degrees from the Sun.

9. helmikuuta 1996: This new image obtained with ESO's New Technology Telescope (NTT) shows the split nucleus of comet Schwassmann-Wachmann 3.

9. helmikuuta 1996: In the context of a comprehensive Key-Programme , carried out with telescopes at the ESO La Silla Observatory, a team of European astronomers [1]. has recently obtained radial velocities for more than 5600 galaxies in about 100 rich clusters of galaxies. With this programme the amount of information about the motions of galaxies (the kinematical data) in such clusters has almost been doubled. This has allowed the team to study the distribution of the cluster masses, and also the dynamical state of clusters in new and interesting ways.

9. helmikuuta 1996: One more cosmic mirage has been found with the ESO 3.5-metre New Technology Telescope (NTT). It consists of two images of the same quasar, seen very close to each other in the southern constellation of Hydra (The Water-Snake).

2. helmikuuta 1996: This photo was obtained on 15 January 1996 and shows the progression of the work on the enclosure for VLT Unit Telescope no. 1 on Cerro Paranal.

2. helmikuuta 1996: This aerial photo was obtained on 16 January 1996 and shows the progression of the work at the VLT Observatory on Cerro Paranal in the Chilean Atacama desert, about 130 km south of the town of Antofagasta.

19. tammikuuta 1996: How many moons has Saturn, the second-largest planet in the solar system? Until recently, the best answer was eighteen, ranging from innermost Pan that circles the planet 75,000 km above the cloud tops in a little less than 14 hours, to distant Phoebe, 13 million km away in a reverse ('retrograde') 550-day orbit [1]. Now the situation is less clear.

12. tammikuuta 1996: For some time, the astronomical community in Australia has expressed interest in closer ties to ESO. One of the main reasons is the construction of the ESO Very Large Telescope (VLT), of which the first 8.2 m unit telescope is scheduled for completion less than 2 years from now.

5. tammikuuta 1996: A few months ago, Periodic Comet Schwassmann-Wachmann 3 underwent a dramatic and completely unexpected, thousand-fold brightening. At that time, the cause for this interesting event was unknown. However, observations with the two largest ESO telescopes have now shown that the "dirty snowball" nucleus of this comet has recently split into at least four individual pieces. There is little doubt that the outburst and the splitting event(s) are closely related and that the greatly increased dust and gas production is due to "fresh" material of the icy cometary nucleus becoming exposed to the surrounding space for the first time.

5. joulukuuta 1995: As the ESO Very Large Telescope (VLT) rapidly takes on shape, Europe has just come one step closer to the realisation of its 556 million DEM astronomical showcase project.

20. marraskuuta 1995: Today, forty 16-18 year old students and their teachers are concluding a one-week, educational `working visit' to the ESO Headquarters in Garching (See ESO Press Release 14/95 of 8 November 1995). They are the winners of the Europe-wide contest `Europe Towards the Stars', organised by ESO with the support of the European Union, under the auspices of the Third European Week for Scientific and Technological Culture.

20. marraskuuta 1995: New observations of the spectrum of the rapidly spinning neutron star (the `pulsar') in the Crab Nebula have been carried out with the ESO 3.5-metre New Technology Telescope (NTT) by a group of Italian astronomers [1]. Because of greatly improved spectral resolution which allows to register even very fine details in the pulsar's spectrum, they are able to determine for the first time with high accuracy the overall dependance of the emission on wavelength, i.e. the 'shape' of the spectrum. Quite unexpectedly, they also detect a hitherto unknown 100 A (10 nm) broad 'absorption dip', which can be securely attributed to the pulsar. These results open an exciting new window for the study of the extreme physical processes close to a pulsar.

13. marraskuuta 1995: This photo shows the state of construction of the enclosure (`dome') for VLT Unit Telescope No. 1 on Paranal in late October 1995. It will be ready in 1996, and will later serve to protect the first 8.2-metre VLT telescope, for which the 'first light' is foreseen in late 1997/early 1998.

13. marraskuuta 1995: In 1989, the European Southern Observatory (ESO), the European Organisation for Astronomy, awarded to REOSC, a subsidiary of the SFIM Group and located in Saint Pierre du Perray (France), a comprehensive contract for the polishing of four 8.2-metre diameter mirrors for the unit telescopes of the ESO Very Large Telescope (VLT) project. These mirrors are the largest ever manufactured and polished. This contract comprises not only the polishing and high-precision optical testing of each giant mirror, but also the safe condition of transportation of the blanks which were manufactured by Schott Glaswerke in Mainz (Germany). In order to fulfill the contract, REOSC conceived, built and equipped a novel, high-tech workshop which would allow to polish and test the mirrors, each of which has a surface area of more than 50 square metres.

8. marraskuuta 1995: Following the very successful events of 1993 and 1994 [1], ESO again opens its doors for an 'educational adventure' next week. It takes place within the framework of the 'Third European Week for Scientific and Technological Culture', initiated and supported by the European Commission. On Tuesday, November 14, 1995, about forty 16-18 year old students and their teachers will converge towards Munich from all corners of Europe. They are the happy winners of a Europe-wide astronomy contest (`Europe Towards the Stars') that took place during the summer and early autumn. Their prize is a free, week-long stay at the Headquarters of the European Southern Observatory. During this time they will work with professional astronomers and get a hands-on experience within modern astronomy and astrophysics at one of the world's foremost international centres.

23. lokakuuta 1995: Astronomers from the University of Leiden have discovered an extremely distant, enormous gas cloud. It is probably a 'cocoon' from which one or more galaxies are in the process of being born, soon after the Big Bang. The observations also indicate that this gas cloud is slowly rotating, an entirely new result of great cosmological significance. The discovery was made with the ESO 3.5-metre New Technology Telescope (NTT) at La Silla in Chile by a team consisting of Rob van Ojik, Huub Röttgering, Chris Carilli, George Miley and Malcolm Bremer from Leiden Observatory (The Netherlands) and Duccio Macchetto of the European Space Agency (ESA) stationed in Baltimore, U.S.A. Their extensive observations are reported in an article accepted for publication in the professional European journal `Astronomy and Astrophysics' and also as a chapter of van Ojik's Ph.D. thesis which is defended at the University of Leiden on October 25. This exciting result casts new light on one of the most important questions of modern cosmology, i.e. how lumpy galaxies were 'born' out of the extremely smooth fireball produced during the Big Bang.

23. lokakuuta 1995: Adaptive Optics (AO) is the new "wonder-weapon" in ground-based astronomy. By means of advanced electro-optical devices at their telescopes, astronomers are now able to ``neutralize'' the image-smearing turbulence of the terrestrial atmosphere (seen by the unaided eye as the twinkling of stars) so that much sharper images can be obtained than before. In practice, this is done with computer-controlled, flexible mirrors which refocus the blurred images up to 100 times per second, i.e. at a rate that is faster than the changes in the atmospheric turbulence.

15. syyskuuta 1995: Four European astronomers [1] have taken advantage of the superb imaging quality of the ESO 3.5-metre New Technology Telescope (NTT) at the La Silla observatory, to detect a galaxy at an extremely large distance. They conclude that its redshift [2] is z = 4.4; thus, this galaxy is by far the most remote ever detected. In fact, it has taken its light about 90 percent of the age of the Universe to reach us, and we now observe this early object as it appeared, only 1 - 2 billion years [3] after the Universe was created in the Big Bang. Still, the galaxy contains a considerable amount of elements that must have been produced in stars. This proves that stars were formed in normal galaxies, already before this very early epoch.

13. syyskuuta 1995: The construction of the ESO Very Large Telescope (VLT) advances rapidly, both in Europe and in Chile. These three photos show some of the main mechanical parts of the first 8.2-metre telescope, as they presented themselves in Milan (Italy) on Thursday, September 7, 1995. Two versions of these photos, one smaller and one larger and with better image resolution, are accessible for convenient transfer over the networks.

11. syyskuuta 1995: Comet Hale-Bopp is known to possess a bright coma, despite its large distance from the Sun, almost 1,000 million km. Observations have shown that this coma consists of dust particles of different sizes that have been ejected from the comet's nucleus.

5. syyskuuta 1995: A brand new image of comet Hale-Bopp, showing its famous jet that comes out of the nuclear region, has just been released.

1. syyskuuta 1995: A new image of comet Hale-Bopp, taken at ESO's observatory in La Silla, sheds new light on the structure of this peculiar comet.

30. elokuuta 1995: This series of three photos of the unusual Comet Hale-Bopp demonstrates that the comet is much larger than thought so far. In fact, its nucleus is surrounded by a dust cloud that measures more than 2.5 million kilometres across. Note that because of the wide field they represent, each of the images is available in two sizes, the larger of which has considerably better resolution.

25. elokuuta 1995: A very unusual comet was discovered last month, on its way from the outer reaches of the solar system towards the Sun. Although it is still situated beyond the orbit of Jupiter, it is so bright that it can be observed in even small telescopes. It has been named `Hale-Bopp' after the discoverers and is already of great interest to cometary astronomers.

25. elokuuta 1995: In the evening of August 17, 1995, famous comet hunter William Bradfield (Australia) discovered his seventeenth comet. He found the comet as a 6th magnitude object with a tail longer than 1 degree in the southern constellation Crater. Soon thereafter, observations were made at the ESO La Silla Observatory with various telescopes.

22. elokuuta 1995: This series of four photos was taken on Sunday, August 6, 1995, on the top of the Paranal mountain, where the world's largest telescope, the ESO 16-metre equivalent Very Large Telescope , is now being installed. The VLT will consist of four 8.2-metre unit telescopes which can also be coupled. Together with some smaller, moveable telescopes, to be installed later, the four large telescopes will form the VLT Interferometer (VLTI) , a unique instrument that will allow extremely sharp images to be obtained. The first 8.2-metre telescope is expected to be in place in late 1997/early 1998.

22. elokuuta 1995: On Sunday, July 30, 1995, at 1:15 hrs, the Antofagasta region was struck by a strong earthquake, reaching 7.8 on the Richter scale. Three people died and more than 130 houses and buildings were damaged beyond repair. The port also suffered damage.

22. elokuuta 1995: Moving steadily closer to the Sun, Comet 1995 Q1 (Bradfield) can no longer be observed with the larger telescopes at La Silla. Nevertheless, Guido Pizarro succeeded in obtaining one more image with the ESO Schmidt telescope last evening (21 - 22 August 1995). At the moment of the 10 minute exposure, the comet was only 26 degrees from the Sun. This is most likely to be the last image of this comet that will be made from the ESO observatory.