MDM Observatory 1.3m Telescope Observing Report for 2011 Jul 04

Observer(s): Halpern, Gordon
Institution(s): Columbia

Instrument: Templeton

Worked for 1.5 hours (part of the night)
Conditions were Mixed most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Beg: Overcast, Winds Light & Variable
   Mid: Overcast, Winds Light & Variable
   End: Patchy Clouds, Winds Light & Variable

Observing Summary:

Opened briefly in a sucker hole.
Did not fill templeton as this is the end of
the observing run.
Here is a final summary of this observing run:

It's too bad that the 1.3m is so handicapped,
because some of it properties are much improved
by the upgrade.  Notably, the focus is much better,
and stable over the sky.  Unlike previously,
seeing of 1.2 arcseconds or better can often be
achieved.  This could be quite a decent telescope
for its size.

Without guiding, the tracking is a little bit
fast, by about 0.03 seconds of time per minute,
and can be seen to trail in an exposure
longer than about 1 minute.  It also moves
to the north, at about 0.25 arcseconds per minute.

Frequently the telescope jumps 20-30 arcseconds
to the south even when not guiding.  Sometimes it
comes back to the original position in several steps
over the next few seconds.  At its most frequent,
this behavior can occur roughly once per minute,
and continue indefinitely, or until the observer
runs out of patience.  But sometimes the telescope
can go for hours without jumping.  It may behave
better when further north. I put a sample series
of images showing the typical bad behavior in

/data/tambora/obs13m/jumping/

Guiding is always a losing proposition; it just
ensures that the declination will be unstable.
By the way, with the new Maxim DL software, it
is impossible for the guider to establish the
guide rates empirically using the automatic
calibration feature, because the telescope doesn't
respond in a normal manner to guide commands.  
Each time I tried to calibrate, the derived
rates would vary by a factor of 2 at least.
So I just put in a guess for the rates.  In any
case, there is no point in trying to figure out
the optimal guiding parameters, because there
aren't any until the basic telescope tracking
can be fixed.


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Submitted on 2011 Jul 5 [2:45:43]