Untitled - ESO

The accelerometers enable the feeding of
direct measurements of the actual vibration
signals to the VTK system. Through
this effort the original residual OPD variations
of 480 nm were reduced by the end
of the year to 30 nm. The VLTI team is
confident that, with a robust implementation
of these new vibration-suppression
techniques and further elimination of the
major vibration sources, fringe-tracking
with three UTs and AMBER can be delivered
to science operations by the end
of 007 – just in time for the observatory
to receive PRIMA, the next VLTI facility,
which is expected to further push the
sensitivity of the VLTI and provide relative
astrometric measurements of the highest
precision.
VST and VISTA Survey Telescopes
The construction, integration and test-
ing of the .4-m optical VLT Survey Telescope
(VST) and its subsystems con-
tinued in Naples during 006 by the
Osservatorio di Capodimonte. The disassembly
of the main telescope structure
started in collaboration with ESO at the
end of the year, to prepare for the shipment
to Paranal where the reintegration
of the telescope is planned during the
second half of 007.
34
ESO Annual Report 006
The primary mirror cell and the secondary
mirror unit, however, remain in Naples for
their completion. The VST secondary
mirror optics were completed and shipped
to Paranal early this year while the .4-m
primary mirror remained at the manufacturer’s
premises for its completion.
The 4. -m infrared survey telescope
VISTA is currently under construction by
the VISTA project office on its own peak
about 1500 m from the Paranal summit.
The enclosure was essentially completed
and accepted before the telescope
structure arrived on 11 May 006. Since
then, the telescope assembly progressed
rapidly and the VISTA telescope had
entered a phase of intensive testing and
tuning by the end of the year. At the same
time, the VISTA facility was integrated
into the power and computer networks of
the Paranal site to prepare for its future
operation. VISTA – as all telescopes on
Paranal – will eventually be operated from
the same common control room as the
VLT and the VLTI.
A dedicated coating unit arrived in September
and was successfully commissioned
in the following months. The
VISTA coating unit is the only facility
on Paranal that allows the coating of
mirror surfaces with a layer of silver (instead
of aluminium as used for the
VLT mirrors) to provide highest reflectivity
of the optical surfaces in the near-infrared
wavelengths where VISTA is going to
survey the sky.
The VISTA telescope is now awaiting the
arrival of its optics and its instrument.
The primary and secondary mirrors are
still in the phase of final polishing in Europe,
and are now only expected to arrive
on Paranal in the second quarter of 007.
Commissioning of the telescope and the
formal handover to ESO are planned to
take place in the second half of 007.
In December, the IR Camera that was
developed at the Rutherford Appleton
Laboratory in the UK was also shipped to
Paranal for arrival in mid-January 007.
VISTA enclosure. The VISTA telescope.