Subject: Minutes, APO 3.5 UC meeting, 02/07/00

From: strauss@astro.Princeton.EDU

Submitted: Thu, 10 Feb 2000 13:42:54 -0500 (EST)

Message number: 413 (previous: 412, next: 414 up: Index)

  Apache Point Observatory 3.5m User's Committee Meeting
		February 7, 2000

Attending: Jeff Brown, Jeff Morgan, Rene Walterbos, Ed Turner, Michael
Strauss, Bruce Gillespie, Chris Stubbs, Alan Uomoto

Absent: Lew Hobbs

  Performance of the optics
  Status of the guider
  Observing Specialists

******************Performance of the Optics************************

Jeff Morgan: The telescope optics are currently capable of routinely
delivering seeing of 0.52".  There is a sag of the secondary support
structure as function of altitude, a bit worse than specs.  This
induces a coma error of 0.1".  We have a plan to correct this sag, so
we should soon get 0.45" images (to the extent that the atmosphere
gives us such good conditions).  At that point, we will be dominated
by astigmatism.  This is due to mounting problems with the primary,
which have been around for a long time (but we're only now properly
sensitive to it, due to the new secondary).  There may also be damage
to one of the flex pivots on the secondary support (which may cause
the increased wind-shake problems seen recently).  If we can get rid
of this problem, we'll have a telescope whose optics can deliver 0.24"
images, which is close to the original design spec of the telescope.

There are still dynamical problems with the mounts, so the telescope
can deliver this kind of image for only a short time (a few seconds).
Having said this, people have been seeing truly wonderful seeing in
recent weeks, as good as 0.6" in moderately long exposures in the

**************************The guider*******************************		
  The camera on the autoguider has gone down (see apo35-general #412).
With DIS you can guide off the slit viewer manually.  But there is no
guider capability at the moment with SPICAM or GRIM.  There was a
glycol leak in the camera head onto the electronics.  It was sent back
to the manufacturer's twice.  When it was first sent back, there were
problems with the full-well depth and charge transfer.  They haven't yet
found the problem, although Jeff thinks the problem is just some
improper voltage settings.  They will give us some relevant numbers of
voltage measurements "as soon as possible".  We won't get the camera
back before the end of the week, and perhaps somewhat later than that.

**************************Observing Specialists***********************
  Personnel: We're sad to learn that Karen Loomis has tendered her
resignation.  We've offered a job again to Camron Hastings, who has
accepted.  He will start again on 1 April.  Eddie Bergeron will come
back for two weeks in March to help the current observing
specialists and bridge the gap until Camron starts. 

  The 3.5m User's Committee wishes to express its enthusiasm for the
tremendous service Karen has given to the observatory over these many
years, its regret that she will no longer be working with us, and its
best wishes for the new directions she is taking her life. 

Goddard InSb camera: Bernie Rauscher, who was one of the PI's on 
GRIM, is now at STScI, and is getting involved in this new instrument.
There is also a possibility that Goddard may be doing some significant
upgrades, including possible Integral Field Unit capabilities and
possible automation of such things as filter changes.  

  There was a recent event when an observer called less than 24 hours
before their night, saying, "Oh, I've got another observing run on
another telescope at the same time; could you please observe the
following targets for me?"  Please do not assume that the observing
specialists are free at a moment's notice to do service observing!  We
will do service observing for compelling reasons, decided on well
beforehand.  Even better is to set up scientific collaborations
between collaboration astronomers and observing specialists.

  Work is on-going on the design of the new top-end, with discussions
between Stubbs and Kibblewhite underway.

  Walterbos: A fellow from Rio de Janeiro, Marcos Nunos, with
electronics and optics experience, is interested in coming to UW to
work on the DIS upgrade, for something like three months.  His salary
would be covered from his job in Brazil; we would pay for his local
expenses (food and lodging).  

  We have both web-based schedules, and hardcopy faxed schedules.  We
have decided to go entirely with the web-based schedule; let Ed Turner
know if this causes any trouble.  Postscript files would still be
available to download and generate local hardcopies, as they are now.

  Turner is generating a slight update to the observing request form
to clarify which DIS gratings, filters, slits, etc., people actually need.

  We discussed whether people who have not observed on the telescope
for many years should still be considered certified for observing
remotely.  We have no policy in place of a "statute of limitations",
but perhaps should consider one.  We discussed this issue, but came to
no specific conclusion. 

  Gillespie: We're thinking about the telescope schedule for the rest
of the year.  At this writing, we don't anticipate any major shutdowns
during calendar year 2000.  In particular, there will be no shutdown
for realuminizing.

 No corrections to last month's meeting minutes. 

  The next meeting will be held on March 13 at 11:30 AM East Coast

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