Lehdistötiedotteet

10. syyskuuta 1987: A newly discovered quasar (eso8712) has been found to have a record redshift [1] of 4.11 and is therefore the hitherto most distant known object in the Universe.

15. heinäkuuta 1987: The discovery of what may be the first true binary quasar has been reported by a European-American team of astronomers using a combination of optical, spectral, and radio observations. The pairs of nearly identical quasars, separated by only 4.2 arcseconds projection on the sky, have a redshift of 1.345, corresponding to a distance of some 12 billion light-years from Earth (according to the standard cosmological distance scale) and are apparently associated with the radio source PKS 1145-071 in the constellation Crater [1].

8. heinäkuuta 1987: The first full-scale, international meeting about the bright Supernova 1987A in the Large Magellanic Cloud (LMC) was held at the European Southern Observatory in Garching near Munich on July 6 - 8, 1987. ESO was a natural meeting place in view of the many different observational studies of SN 1987A which have been carried out at the ESO La Silla observatory.

3. heinäkuuta 1987: The first observations of a long-lived radioactive isotope outside the Solar System indicate that the Universe may be younger than previously thought. Using one of the world's most powerful spectrometers, located at the ESO La Silla observatory in Chile, Professor Harvey R. Butcher of the University of Groningen, The Netherlands, has detected for the first time the radioactive element Thorium-232 in stars. A comparison of its abundance in old and young stars failed to show the expected differences. This means that the total age of Thorium-232 in these stars must be smaller than about 10 Gyr [1], instead of the previously estimated 16 - 18 Gyr.

16. kesäkuuta 1987: Of all exotic objects predicted by current theories, none are as elusive as the Black Holes. Despite great efforts, their existence has never been unambiguously proven by astronomical observations.

25. toukokuuta 1987: An exhibition about the European Southern Observatory will be open to the public at the Heysel Planetarium, Brussels, Belgium, on June 6 - 15, 1987 (all days, also during the weekends, from 10:00 to 16:30). It has been organized in a collaboration between ESO, the Brussels Planetarium and the Belgian National ESO Committee.

14. toukokuuta 1987: In these days, northern astronomers have reason to envy their colleagues in the south. By chance, the two main events in observational astronomy at this moment both occur deep in the southern sky and they can therefore not be observed from the astronomical centres in the northern hemisphere.

31. maaliskuuta 1987: “This supernova is different from all others observed so far".That is the unanimous conclusion of astronomers who have observed supernova 1987A in the Large Magellanic Cloud (LMC) with ESO telescopes since the explosion in late February (see ESO 04/87 and ESO 05/87). The collective results from the ESO La Silla observatory of no less than 38 astronomers have now been submitted to the European journal Astronomy & Astrophysics where they will appear in six "Letters to the Editor'' in the May(I) 1987 issue. These articles cover astrometry, optical and infrared photometry, polarimetry, optical and infrared spectroscopy and high-resolution spectroscopy; they are immediately available in ESO Preprint no. 500 (March 30, 1987) which can be obtained by request to the ESO Information and Photographic Service.

3. maaliskuuta 1987: One week after the explosion of a bright supernova (1987A) in the Large Magellanic Cloud (ESO 04/87), and after intensive observations at the European Southern Observatory and elsewhere in the southern hemisphere, it is now possible to draw several important conclusions about this unique event.

26. helmikuuta 1987: Stars do not live forever - they are born and they die. All stars are born by contraction of matter in large interstellar clouds of gas and dust, but they do not all die in the same way. Heavy stars appear to end their active lives in gigantic supernova explosions (eso8608) while less massive stars (like our Sun) follow another path.

25. helmikuuta 1987: Astronomers all over the world are highly excited about the sudden explosion of a supernova in the Large Magellanic Cloud (LMC), a small satellite galaxy to our own Milky Way Galaxy. The LMC is the nearest, external galaxy; its distance is only about 180.000 light years.

5. helmikuuta 1987: A European group of astronomers has discovered an extreme example of `quasar-like' activity in an otherwise normal radio galaxy. What is most remarkable in this case is that the activity occurs not at the galaxy's centre, but in its halo at a distance of about 30000 light years from the centre. This important result, which is based on observations at the ESO La Silla observatory, opens new and exciting lines in galaxy research [1].

5. tammikuuta 1987: Based on observations obtained at the European Southern Observatory (ESO), astronomers at the Space Telescope Science Institute (STScI) have uncovered the strongest evidence yet for the presence of a giant planetary or protoplanetary system accompanying a nearby star [1].

4. joulukuuta 1986: An unusual "astro-detective" investigation came to a successful conclusion today, when a long lost planet in the solar system was finally found again. This planet which carries the name "MALLY" and the number "1179" had been missing for 55 years, and was last seen in 1931. Its faint image was now identified on photographic plates obtained with the ESO Schmidt telescope during a dedicated search programme. The accurate orbit of MALLY in the solar system [1] has now been determined, ensuring that MALLY will never be lost again. This work was carried out by Drs. Lutz Schmadel of the Astronomisches Rechen-Institut in Heidelberg, FRG, and Richard M. West of the European Southern Observatory.

5. marraskuuta 1986: For the first time, an accurate and direct determination of the diameters of the outermost planet Pluto and its moon, Charon, has been made. On the basis of measurements of light changes during eclipses, Pluto was found to have a diameter of 2200±140 km. Charon is approximately half the size; the diameter is 1160±100 km. Charon moves in an almost perfectly circular orbit around Pluto; the orbital period is 6.38 days and the mean distance is 19400 km.

4. lokakuuta 1986: The ESO Very Large Telescope (VLT) project [1] has passed an important milestone on its way towards realization. This week, more than 80 leading scientists and engineers from the ESO member countries (and beyond) made a detailed assessment of this ambitious project, which aims at the construction of the world's largest optical telescope. There was unanimous agreement that the present concept is near the optimal, that it is technologically feasible and can be realized within approximately 10 years after funding has been decided upon, and that it will allow European astronomers to perform new and spectacular investigations of the universe, unparalleled elsewhere. Completion is aimed at in 1997 but part of the VLT may become operational already in 1993.

13. toukokuuta 1986: Detailed observations of a bright supernova in the peculiar galaxy NGC 5128 = Centaurus A, have led astronomers at the European Southern Observatory to believe that this galaxy is much closer to us than previously thought. It is the nearest, strongly radio-emitting galaxy and is as such an object of crucial importance in modern astrophysical research. The revised distance is 7 - 10 million light years or only 3 - 4 times farther away than the Andromeda Nebula. Cen A may therefore even be an outlying member of the Local Group. The total radio emission energy corresponds to the conversion to pure energy (annihilation) of a mass equal to 10.000 suns.

6. maaliskuuta 1986: This spectacular image of Comet Halley, rising above the eastern horizon, was obtained at the La Silla observatory during the morning of February 22. It was made by superposing 6 exposures (total 9 min.) with the wide-field CCD camera which was specially designed for the study of Comet Halley. The image measures 5.5 x 9 degrees across and covers the 500 - 1100 nm spectral region (green near infrared). Each pixel (image element) measures 31 x 31 arc-seconds.

3. maaliskuuta 1986: After several years of intensive studies, the European Southern Observatory now releases information to the public about its 16 metre telescope project. The concept here shown is the result of an extensive collaboration between European science and industry.

26. helmikuuta 1986: 23 February was the last morning when Comet Halley could be seen in a dark sky. During the next two weeks, the moonshine will hamper further detailed observations of the incredibly complicated tail structure which was recently detected at the European Southern Observatory on La Silla.