Subject: 3.5m User's Committee minutes, January 11, 1999

From: Michael Strauss

Submitted: Tue, 19 Jan 1999 16:18:03 -0500 (EST)

Message number: 333 (previous: 332, next: 334 up: Index)

 Apache Point Observatory 3.5m User's Committee Meeting

 January 11, 1999

 Attending:  Ed Turner, Jeff Brown, Bruce Gillespie, Chris Stubbs, Alan
 Uomoto, Rene Walterbos.

 Not attending: Ed Kibblewhite, Michael Strauss


 Echelle status
 New 2ndary report
 Tertiary rotation project
 Top-end enhancements, wind shake?
 SDSS science synergy

 *************Echelle status*************

 Echelle commissioning proceeds with good progress and no very serious
 problems so far.  Stellar spectra have been obtained, and many performance
 parameters of the instrument have been ascertained to first order (see Don
 York's message in apo35-general, dated 11 January 99).  Work continues on
 instrument alignment and telescope collimation/pointing, and the remote
 interface is continuing to be wrung out.  Science commissioning will
 continue through January and February, and user and engineering
 documentation will be delivered.  We still expect the instrument will be
 available for scheduled science use by the general ARC community for the
 2nd quarter.

 *************New 2ndary report*************

 Alan Uomoto:

 There has been little news in the past month, other than a delivery in
 January would be "difficult," and "possible" in February--we should use 31
 January as the rough planning date for delivery.  Alan is planning a trip
 to the Steward Observatory Mirror Lab in the near future, and the details
 of mirror acceptance and delivery need to be worked out.  Jon Davis is
 designing, and having built, the  necessary parts to mount the new mirror
 when it arrives or soon thereafter.

 *************Tertiary rotation project*************

 Chris Stubbs:

 The design is done and the fabrication is underway, expected complete by
 mid-February and installed on the telescope in late February.  Need a 7-day
 shutdown which would pre-empt scheduled science with ~two-week warning.
 There followed some group discussion about permanently mounting other
 instruments on the telescope, once semi-automated tertiary rotation is
 completed.  This will usually require a new rotator and guider, costing an
 estimated $50k per port.  We will consider the budgetary angle on doing
 this, port by port, over the next few years.

 *************Top-end enhancements, wind shake?*************

 Ed Kibblewhite is heading up a design for major enhancements to the 2ndary
 support structures and top-end truss, as detailed in the previous Users'
 Committee minutes.  No report available at this time.

 There are recent observer reports of significant wind shake, and the group
 wondered if something in the 2ndary support structures has come loose or
 broken.  Jon Davis inspected the 2ndary mechanicals and found nothing
 amiss, apart from a loose bolt which he believes would not contribute to
 wind shake.  The bolt was tightened and we are looking for further
 occurrences of the purported problem.

 *************SDSS science synergy*************

 Given the recent and dramatic examples of SDSS discovery science which is
 supplemented by follow-up 3.5-m observations, the group discussed the need
 to provide more formal and expeditious 3.5-m opportunities to SDSS
 researchers.  Apart from the institutional conflicts, it was decided that
 the current ad hoc system of applying for 3.5-m time in the usual way is
 sufficient for now, and also that DD time could be requested to provide
 3.5-m observations in support of SDSS on relatively short notice, when
 needed.  A more formal mechanism for this is not foreseen as necessary, at
 least not anytime soon.


 Last month's minutes are approved.


 Next meeting, Monday, February 8, 1999, 12:00 noon Eastern Time

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