Happy Anniversary, VLT ! Five years at the service of Europe's astronomers(Forwarded)

ESO Education and Public Relations Dept.

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For immediate release: 1 April 2004

ESO Press Release 06/04

Happy Anniversary, VLT !

Five years at the service of Europe's astronomers

One of the world's most advanced astronomical research facilities, the ESO Very
Large Telescope (VLT) at the Paranal Observatory in the Chilean Atacama desert,
celebrates an important anniversary today.

On April 1, 1999, and following almost one year of extensive tests and careful
trimming of its numerous high-tech parts, the first 8.2-m VLT Unit Telescope,
Antu (UT1), was "handed over" to the astronomers. Since that date, science
operations with this marvellous research tool have been continuous and
intensive. Kueyen (UT2) started normal operations exactly one year later. Yepun
(UT4) was offered to the scientific community in June 2001, while Melipal (UT3)
followed in August 2001 [1].

Ever since, all four VLT Unit Telescopes, with an ever-growing suite of highly
specialised, extremely powerful astronomical instruments have been in full
operation, 365 nights a year. And this with unequalled success, as demonstrated
by a long list of important scientific results, including a substantial number
of exciting discoveries that are now opening new horizons in astrophysics.
Moreover, thanks to heroic and persistent efforts by the dedicated teams of ESO
scientists and engineers, the "downtime" due to technical problems has been very
small, about 3 per cent, a number that is unequalled among the world's large
telescope facilities. In addition, the weather conditions at the Paranal site in
the dry Atacama desert in Northern Chile are truly excellent -- this is indeed
one of the best locations for astronomical observations on the surface of the
Earth -- and the corresponding "weather downtime" has only been around 10 per
cent. This has resulted in an unbelievably low value of total downtime, most
likely a new world record for ground-based 8-10 m class telescopes.

VLT strong points

The Very Large Telescope (VLT) is the world's largest and most advanced optical
telescope. It comprises four 8.2-m reflecting Unit Telescopes (UTs) and will in
due time also include four moving 1.8-m Auxiliary Telescopes (ATs), the first
one of which successfully passed its first tests in January of this year (see
ESO PR 01/04).

With unprecedented optical resolution and unsurpassed surface area, the VLT
produces extremely sharp images and can record light from the faintest and most
remote objects in the Universe. It works at the limit of modern technology,
regularly allowing the scientists to peer into new and unknown territories in
the immense Universe.

Contrary to other large astronomical telescopes, the VLT was designed from the
beginning with the use of interferometry as a major goal. For this reason, the
four 8.2-m Unit Telescopes were positioned in a quasi-trapezoidal configuration.
The light beams from these telescopes, at this moment two-by-two, can be
combined in the VLT Interferometer (VLTI).

It provides the European scientific community with a ground-based telescope
array with collecting power significantly greater than any other facilities
available at present or being planned, offering imaging and spectroscopy
capabilities at visible and infrared wavelengths.

Seven of the planned ten first-generation astronomical instruments are now in
operation at the VLT. They cover all major observing modes required to tackle
current "hot", front-line research topics:

* the multi-mode instrument FORS1 (FOcal Reducer and Spectrograph) and its twin,
FORS2,

* the Infrared Spectrometer And Array Camera (ISAAC) cryogenic infrared imager
and spectrometer,

* the UVES (Ultra-violet and Visible Echelle Spectrograph) high-dispersion
spectrograph,

* the NAOS-CONICA Adaptive Optics facility producing images as sharp as if taken
in space [2],

* the VIsible Multi-Object Spectrograph (VIMOS) four-channel multiobject
spectrograph and imager -- allowing to obtain low-resolution spectra of up to
1000 galaxies at a time,

* the Fibre Large Array Multi-Element Spectrograph (FLAMES) that offers the
unique capability to study simultaneously and at high spectral resolution 100
individual stars in nearby galaxies.

The remaining instruments -- the high-resolution infrared spectrograph CRIRES,
the Mid Infrared Spectrometer/Imager VISIR and the integral field spectrograph
SINFONI -- will be installed in 2004-2005.

The observational statistics prove that these instruments are extremely
efficient -- they have some of the highest "shutter-open times" (i.e. percentage
of the maximum possible observing time during which the instruments are
collecting light from the astronomical objects) ever achieved. The astronomers
are well served in this respect: the ISAAC instrument, for example, continues to
be in the highest demand and has now performed smoothly during more than 1000
nights and two others, UVES and FORS, are now approaching the same number.

Working together with astronomers and engineers at many research institutes in
the ten ESO member countries, ESO is now in the process of defining second
generation instruments and feasibility studies are well under way. Among the
prime projects in this direction are a cryogenic multi-object spectrometer in
the near-infrared 1 to 2.4 um range ("KMOS"), a medium-resolution wide-band
(0.32 to 2.4 um) spectrometer ("X-shooter"), as well as a wide-field 3D optical
spectrometer ("3D deep-field surveyor") and a high-contrast, adaptive optics
assisted, imager ("planet finder").

In addition to these highly innovative instruments for the VLT UTs, specific
instruments that will work with the combined light from several of the
telescopes have also been conceived. The interferometric instrument MIDI will be
offered to the astronomical community from today (April 1, 2004), fulfilling the
VLTI promise. Great efforts have indeed gone into making observations with this
very complex science machine as user-friendly as possible. Contrary to what is
normally the case in this technically demanding branch of astronomy, scientists
will find interferometric work at the VLTI quite similar to that of using the
many other, more conventional VLT instruments.

Science with the VLT

The impressive battery of top-ranking instruments, coupled with the enormous
light-collecting power of the VLT, has already provided a real research bonanza
with many outstanding scientific results, some of which have been true
breakthroughs. They include the amazing new knowledge about the Black Hole at
the Galactic Centre, the farthest galaxy known, the most metal-poor and hence,
oldest stars, accurate cosmochronological dating by means of Uranium and Thorium
spectral lines, high-redshift galaxy rotation curves, micro-quasars, properties
of the optical counterparts of gamma-ray bursts, high-redshift supernovae, etc.
[3]. All of these advances attest to the power of the VLT and its mode of
operational. Not to be forgotten is also the beauty of many of the stunning
images obtained with this telescope, one of which was voted amongst the 10 most
inspirational astronomical images of the past century [4]. Look at the numerous
and detailed ESO Press Releases for more examples of research achievements from
the VLT.

This trend is also apparent in the productivity of the telescopes. The number of
research publications resulting from VLT work in top ranking astronomical
journals is steadily increasing with a total close to 700, hereof 250 in 2003
alone. Moreover, research articles based on VLT data are in the mean quoted
twice as often as the average.

The very high efficiency of the VLT "science machine" now generates huge amounts
of data at a very high rate. These are stored in a permanent Science Archive
Facility at ESO headquarters, which is jointly operated by ESO and the Space
Telescope European Coordinating Facility (ST-ECF). From here, data are
distributed daily to astronomers on DVDs and over the World Wide Web. The
archive facility has been conceived and developed to enable astronomers to
"mine" very efficiently the enormous volumes of data that is collected from the
VLT. The archive now contains more than 1 million images or spectra taken by the
four UTs with a total volume of about 50 Terabytes (50,000,000,000,000 bytes) of
data. This corresponds to the content of about 25 million books of 1000 pages
each; they would occupy more than 1000 kilometres of bookshelves!

Looking towards the future

Says Catherine Cesarsky, ESO Director General since 1999: "The Paranal
Observatory has already given rise to an impressive number of scientific
results, many of which could not have been obtained elsewhere. Overall, the VLT
has been a most remarkable success, and will contribute to science at the
highest level for years to come -- a fantastic achievement of which we can all
be justifiably proud."

The work is now underway at full power to provide second-generation instruments
for the VLT, to add three more Auxiliary Telescopes to the VLTI and to
complement this unique research facility with the two wide-field survey
("pathfinding") telescopes -- one to work in the visible part of the spectrum
(the 2.5-m VST), the other in the infrared (the 4-m VISTA) -- now being
constructed at Paranal.

Roberto Gilmozzi, director of Paranal Observatory, looks forward: "Ever more
exciting times lie ahead for Paranal with new instruments like VISIR and SINFONI
and the laser guide star, all of them coming this year. Five years after the
start of operations on UT1, the observatory operates its telescopes with very
little time set aside for engineering (less than 10%) and very low technical
down time. Combined with excellent weather and great image quality, we provide
the European community with unsurpassed observing capabilities. As director of
this observatory since 1999, I have been privileged to be part of this adventure."

The VLT is a fine example of the vast benefits of pooling resources from several
countries and it is a flagship of contemporary European research. There is
little doubt that for many years to come, ESO's Paranal Observatory with its
powerful and efficient facilities will continue to play a leading role in
astronomical research.

Information for the media

Associated material can be found on the corresponding Press Events webpage.

Notes

[1] It had long been ESO's intention to provide "real" names to the four VLT
Unit Telescopes, to replace the original, somewhat dry and technical
designations as UT1 to UT4. In March 1999, at the time of the Paranal
Inauguration, four meaningful names of objects in the sky in the Mapuche
(Mapudungun) language were chosen. This indigeneous people lives mostly in the
area south of the Bio-Bio river, some 500 km south of Santiago de Chile. Thus,
the four Unit Telescopes are now known as: ANTU (UT1; The Sun), KUEYEN (UT2; The
Moon), MELIPAL (UT3; The Southern Cross), and YEPUN (UT4; Venus - as evening star).

[2] NACO is the most powerful adaptive optics system deployed on an 8-m class
telescope allowing to do imaging and spectroscopy at the diffraction limit of
the telescope without the perturbing influence of the atmosphere. Look for
example at ESO Photos 08a-c/04 showing images of Titan, the satellite of Saturn.

[3] The examples given here can be found at : ESO Press Release 02/01 , ESO
Press Release 04/01 , ESO Press Release 24/01 , ESO Press Release 17/02 , ESO
Press Release 19/02 , ESO Press Release 16/03 , ESO Press Release 26/03 , ESO
Press Release 04/04 .

[4] The twenty best of these stunning images are now available at the Top 20
webpage with printing quality images.

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