ABSTRACT

1
AUTOMATED TELESCOPES AT THE UNIVERSITY OF TORONTO
S.W. Mochnacki (University of Toronto), M.
Castel (ROBOsky)
ABSTRACT At the University of Toronto, we try to
give our undergraduates the opportunity to do
real research, and to promote this we have
modernized our undergraduate observatories. We
have retrofitted for automated operation the 40cm
Boller and Chivens Cassegrain reflector at the
St. George Campus and the 30cm Questar Maksutov
on a Byers mount at the Scarborough Campus. We
have adapted commercially available "off the
shelf" equipment and software developed mainly
for the advanced amateur market. The 40cm BC
telescope is fitted with an SBIG SGS
spectrograph we have achieved RMS pointing
precision of under 30 arc seconds, and expect to
refine this to about 12 arc seconds. Scripted
operation has been demonstrated, and a Web
interface allows students to obtain observations
using their home computers and the Internet. The
30cm Questar is fitted with a 1024x1024 thinned
back-illuminated CCD, providing an imaging field
of 19 arc minutes square at 1.1 arc seconds per
pixel. Remote operation has been achieved.
Examples of observations with each telescope are
presented, and lessons learned are discussed. We
are grateful for the support of the Faculty of
Arts and Science at the University of Toronto and
Dean Carl Amrhein.
30cm Questar at Scarborough, after renovation.
The FLI CCD is on the left (the box is actually
largely empty and contains the TE cooler heatsink
vanes). An automated filter wheel is shown, but
the motorised focuser is hidden by the camera.
Observing room at St.George (downtown) location.
Telescopes can be used locally as well as
remotely. Control PCs shown.
40cm BC Cassegrain reflector with SBIG SGS
spectrograph and ST-7 CCD camera.
30cm Questar Maksutov on Byers mount, before
modification.

• THE TELESCOPES and INSTRUMENTS
• 40cm f/18 Boller Chivens (1967), on 16th floor
  of the Burton Tower, McLennan Labs, in downtown
  Toronto. The sky brightness has been measured at
  16 per sq arcsec. This telescope has been
  outfitted with an SBIG self-guiding spectrograph
  plus ST-7XE, with an older ST-7 to be fitted on
  the 10cm auxilary refractor telescope. Employing
  TheSky and TPOINT software, pointing accuracy of
  26 arcsec RMS has been achieved in the first
  season, and we expect that 12 arcsec will be
  achieved after improvements this summer. The
  quality of the BC telescope has made
  retrofitting of modern controls (single motor on
  each axis) a rewarding exercise. Slew speeds of
  six degrees per second are possible, but in cold
  weather we slow this down to one or two degrees
  per second.
• 30cm f/15 Questar Maksutov on a Byers mount
  (1980), on the roof of the main building of the
  University of Toronto at Scarborough. This
  telescope is outfitted with a Finger Lakes
  Instrumentation IMG1024S camera for multi-color
  imaging photometry, with a field of view of
  19x19, at 1.1 arc seconds per pixel. An FLI
  CFW-1 wheel has BVRI filters. An SBIG STV camera
  has recently been acquired and will be mounted on
  an auxiliary guide scope. This system will be
  used for variable star photometry in clusters,
  and numerous other student research projects.

Guider chip slit view of Jupiter, during exposure
shown on left. A fainter ghost appears to the
right. Two moons seen.
Spectrum of Jupiter. 100 sec integration,
H-alpha, 1 A per pixel. Dark subtracted

• CONTROL SYSTEM
• Both telescopes use the Astrometric Instruments
  Skywalker 1 system (seen above).
• Microprocessor unit (Skywalker) contains basic
  controller, indexers, guider and encoder
  interfaces, handpaddle interface and additional
  control interfaces. It works closely via
  dedicated serial link with higher-level SkyGuide
  software running on a Windows PC.
• Geckodrive G320 DC Servodrives receive indexer
  pulses from the Skywalker unit and drive Pittman
  DC servo motors equipped with optical encoders.
  The Geckodrives receive the encoder output and
  equate indexer pulses with encoder pulses to
  control the positioning of the DC motors.
• The Skyguide PC program receives commands via
  the ASCOM (or similar) protocol, OR via serial
  line using the LX-200 protocol.
• Skywalker receives direct guiding signals from
  the ST-7 camera (STV in the case of the 30cm
  Questar).
• Separate more powerful computer controls CCD
  cameras, as well as running higher-level
  telescope control software and top-level
  scripting and Web server software.
• Digital Dome Works hardware and software
  controls dome azimuth, shutter and emergency
  services. A weather station is used at each site.
• A Webcam with Web server software, allowing
  remote observers to see what is happening in the
  dome. 30cm also has dial-up remote power and
  reboot control.

• SOFTWARE ENVIRONMENT
• 2 PCs at each site, Windows ME (soon 1 PC on
  Win2000).
• Astrometric Instruments SkyGuide Win.
• Technical Innovations Digital Dome Works and
  RoboFocus.
• ASCOM Astronomy Common Object Model Platform.
• Software Bisque TheSky and Tpoint telescope
  pointing and analysis.
• Diffraction Ltd. MaxIm DL/CCD camera control and
  image processing.
• DC-3 Dreams ACP2. Overall scripted control, Web
  interface.
• DC-3 Dreams PinPoint astrometric solver.
• Hyper Technologies DeepFreeze. Famatech
  Remote Administrator.
• Scripts developed by student Kevin Casteels.
  Further scripts available from Jeff Medkeff and
  other sources on Web.
• IRAF/TABLES/STSDAS/ds9 on undergraduate lab
  Linux boxes. Also IDL, sm, etc.

PERFORMANCE and EXPERIENCE The 40cm
spectrographic telescope was used in local mode
by the 3rd year Practical Astronomy class.
Observations of bright radial velocity standards
showed that typically velocities had RMS errors
of 15 km/s or so. Since the IRAF reductions were
carefully checked by all students, this shows an
instability in the spectrograph. In the summer of
2003, we shall install a proper wavelength
calibration feed, and secure all components. The
30cm telescope has been used remotely, but our
observations showed RFI generated by the
early-model Geckodrives was feeding into the CCD
camera. This is being rectified with later-model
non-dithering Geckodrives, such as those on the
40cm telescope. We also need to eliminate the
need for frequent Argon purges of the camera. We
have been satisfied with the performance of the
Astrometrics Skywalker TCS, and Skyguide is quite
stable on an older dedicated Windows PC.
However, the combination of all the other
software is too much for Windows ME, and we are
upgrading the main computers to Windows 2000. We
also need to frequently update all software
components as new versions are released. We have
had excellent support from, and personal rapport
with, all suppliers. We have automated two good
older telescopes using commercial off-the-shelf
components aimed largely at the amateur market,
at considerably lower cost than buying modern
professional equipment. While we have experienced
and are overcoming some difficulties, we expect
to have students taking observations from home in
the coming academic year.

In the top section, a rectified spectrum of
Pollux is shown. In the lower panel, the
cross-correlation is shown between Pollux and a
telluric-corrected spectrum of Alphard. (From an
undergraduate project report by Duy Nguyen). All
data reductions and analysis by the third year
Practical Astronomy class is carried out using
IRAF, in which the students receive extensive
training. Other tools such as IDL and Mathematica
are available and can be used by the students.