STP Meeting
The scientific policy and allocation of time on the
Schmidt Telescope are determined by a bi-national Schmidt Telescope Panel,
whose membership is drawn from the Australian and British user
communities. The two halves of the panel normally meet independently
every six months, but in December, the full Panel came together for a
two-day meeting at Siding Spring.
As well as allocating time for Semester 1997A, the Panel discussed a wide range of issues covering all aspects of the work of the telescope. They included progress with the current photographic surveys, prospects for the new galactic-plane H-alpha survey, the case for a major new astrometric survey, progress with deep imaging by digital adding, current upgrades to FLAIR and the prospects for a very large-scale FLAIR galaxy-redshift survey.
The STP will present its deliberations in a report to the AAO Board at its March meeting. Current membership of the Panel is Chris Collins (Chair, Liverpool John Moore's), Dick Hunstead (Sydney), Richard McMahon (IoA), David Morgan (ROE), John Norris (ANU) and Fred Watson (AAO). The Secretaries to the British and Australian halves respectively are Sue Tritton (ROE) and Paul Cass (AAO).
H-alpha filter and workshop
There have been delays in the delivery
of the new H-alpha filter due to difficulties
with the supply of the RG610
substrate on which the interference stack is deposited. These problems
have now been resolved, and delivery of the filter from the USA is
expected during February.
An International Workshop to discuss prospects for the Schmidt Telescope's H-alpha galactic plane survey will be held from 16th to 18th April 1997 at the CSIRO Division of Telecommunications and Industrial Physics (formerly Radiophysics) at Epping. The second announcement has now been mailed, and the closing date for registrations is 15th March. Further information can be found here.
Image structure on Tech Pan films
The very fine grain of Kodak Tech
Pan film (now in regular use primarily for U and OR non-survey exposures)
reveals structure in images brighter than the detection limit of the
photograph. This is not a new phenomenon, nor anything intrinsic to Tech
Pan, but is an effect that has tended to be masked by the coarser grain of
the III-a emulsions used previously.
The image structure arises from a misaligment (amounting to about half a millimetre) between the two cemented components of the achromatic corrector. This produces a small amount of wavelength-dependent coma, which is particularly noticeable in the U band. All UKST photographs are taken with optimum focus for the faintest images, and this differs slightly from that for brighter images. The resulting slight defocus of these images is what allows the structure to be seen.
FLAIR upgrades
Experiments on adapting the FLAIR positioning system
to magnetic rather than cemented buttons are progressing satisfactorily.
When the new system is introduced later in the year, it will offer greater
alignment accuracy, reduced fibring-up time and a more palatable working
environment for those carrying out the set-up. Improvements to the
spectrograph are also in progress. FLAIR's WWW pages can be
found here.
Opportunities for large-scale non-survey programmes
During 1998,
two of the telescope's major surveys (the Second-Epoch Red Survey and the
Equatorial Red Survey) will be completed. While other surveys (notably
the all-sky I-band survey and the galactic plane
H-alpha survey) will
continue, there will be scope for larger-scale non-survey requests than
have been possible recently. With Tech Pan film and digital stacking of
images, detection limits approaching those of CCD exposures on
similar-sized telescopes are now practicable over the full 40
square-degree field of the Schmidt. Expressions of interest in non-survey
programmes using these or other techniques are invited. Further
information can be obtained from the telescope
(schmidt@aaocbn3.aao.gov.au) or the UK Schmidt Telescope Unit in Edinburgh
(ukstu@roe.ac.uk).
Visitors to the Schmidt
Summer vacation students Valerie Augustin
(Melbourne) and Antonius Kurnia (UNSW) have now completed their stay at
the telescope. They leave with our good wishes for the future. A welcome
new arrival is Kristen Larson, a postgraduate student at Rensselaer
Polytechnic Institute in New York State, who is spending most of 1997 at
the Schmidt. Kristen works on high latitude dust clouds, and will be
involved with the H-alpha survey---among
other things.
Fred Watson
Erratum/correction
In the ``UK Schmidt Sky Surveys Online'' article in
the July 1996 Newsletter we neglected to acknowledge the work of
Geraint Lewis who wrote a lot of the software we used for the WWW interface
to the APM Catalogues at the AAO. Thanks Geraint!
Michael Drinkwater