Apache Point Observatory 3.5m User's Committee Meeting September 11, 2000 Attending: Bruce Gillespie, Lew Hobbs, Ed Turner, Michael Strauss, Rene Walterbos, Chris Stubbs, Alan Uomoto Agenda: Results from summer shutdown Instrument issues staffing update Miscellaneous Jeff Brown has left WSU, and as they have no further astronomers, they will not be represented in today's phonecon. ***************Accomplishments of summer shutdown******************** Turner: The shutdown concluded essentially on time, and accomplished essentially all the major tasks planned. This was perhaps the most successfully scheduled shutdown yet. The astigmatism term in the image quality error budget, which had been the dominant term (in the 0.3-0.5" range), is now down to of order 0.1", negligibly small, due to improvements in mirror support. We are indeed seeing much better image quality; recently, a 10-minute science exposure with SPICAM had 0.5" seeing; that's fantastic! Gillespie and Stubbs: We are now seeing subarcsec seeing consistently with the telescope. There is still some work on mirror support which is on-going. The telescope ventilation is not what it should be; the thermal time constant of the primary should be 15 minutes, and was measured to be 30 minutes many years ago; but now, there is a sense that it is closer to 3-4 hours (although it is better than it was before the shutdown). We're still seeing spherical aberration in the primary (recognizable now that the much larger astigmatism was taken out), which appears to be related to thermal derivatives in the primary mirror. In any case, the thermal performance of the primary is much better than before the work on the vent tubes behind the mirror was carried out. Our confidence in the diagnostics from the Shack-Hartman sensor has increased considerably; this is turning out to be tremendously useful. There are still problems with holding collimation, as well as windshake; these are of lower amplitude than they used to be. The efficiency of the telescope has also been quite high; users are quite satisfied with the operational efficiency. The appendix is an (unsolicited) recent note from Rene Walterbos about his very positive impressions after a recent observing run. Stubbs: We've (Peter Doherty and Stubbs) put on a pickoff mirror and a fast-guider sensor on SPICAM which is the first component needed for implementing fast guiding. It worked well almost immediately, and has already been used to gather some engineering data on the power spectrum of image motion. It will be a little while before the feedback loop is put in to use this information to control the telescope optics to remove the seeing motion. **********Instrument issues****************** The new camera for the slit-viewer upgrade has arrived on the mountain; it will be incorporated over the next few weeks. Lowenstein has been working on an autoguider for the echelle; this should be available fairly soon. The echelle group will put out documentation very soon on ways to reduce the echelle data, given apparent problems with reductions and the order crowding. We continue to pursue near-IR Imaging cameras, although there nothing new to report. Stubbs on the DIS upgrade: the electronics is being fabricated, and we're working on ways to mount the detectors. We plan to use EEV detectors, with very good UV response. Things are moving! We're thinking about mounting Stubb's wide-field imaging camera at Nasmyth. Gillespie: We had a very successful Fabry-Perot run a few weeks ago. Remember that it is available to the ARC community, and seems to work very well. **********Staffing situation: ******************* Gillespie: We're now down to two observing specialists; Frank Deglman has left. Jack Dembicky, chief Mt. Hopkins 2MASS observer, has been hired. He will start 1 Dec, but he'll work 20 nights before then. Eddie Bergeron has expressed willingness to help for a week or so. We're thinking about ways of rearranging responsibilities to relieve the burden on Camron and Russett in the interim. In any case, as the nights get longer, the burden on them will increase, so it is conceivable that we'll have to shorten nights. Given the amount of turn-over, staffing with three people often puts us in the awkward situation of being down to two observers. Turner is exploring ways to avoid these problems. People should consider students of theirs who might be interested in a career as an observing specialist, and bring the APO opportunity to their attention. *************Miscellaneous***************************** The Board of Governor's meeting is coming up. We want to gather together science highlights from the past year. Thus all user's committee members should let Ed know of recent substantial 3.5m results from their department. Also, send Rene Walterbos (rwalterb@nmsu.edu) lists of publications based on the 3.5m from your department. All observers should make contact with the site staff 24 hours in advance of the run, to confirm instrumental setup and the fact that they are scheduled to observe. We've had a number of miscues on these, and the number has been increasing. Remember, the institution is still charged for unused time. So it really should be the institution to consider whether disciplinary action is appropriate. One possibility is that an automated reminder be sent out by e-mail to all observers, saying two days in advance. People are quite enthusiastic about this idea, and we plan to implement this on an experimental basis in the first quarter of 2001. The University of Minnesota is looking to take over the WSU time. They have already explicitly bought the fourth quarter time, and may join ARC in the future. The Decadal Survey discusses ideas for the National Observing Systems; whereby US observatories work in concert, and/or try to reduce redundancies between telescopes (e.g., all the 8-meters have a similar low-resolution spectrograph; can one be more efficient?). A group of people at NOAO is putting together a workshop in Phoenix in late October to define how this might work in practice. Ed Turner will probably not be able to attend. Different people have very different ideas of how this might work. An obvious telescope that is our sister in this context is WIYN; they are thinking more strongly about remote observing. If they have similar remote observing capabilities, and have complementary instrumentation, then we could imagine sharing time in some way. Last meeting's minutes are approved. Next meeting, 11:30 Eastern time, October 16, 2000 ****************Appendix: Good words from Rene Walterbos************ The past weekend was the first time in a too long period that I had the opportunity to observe with the 3.5-m again, for 4 half nights in a row, onsite. I would like to mention the very positive experience I had with the telescope, and express my appreciation for all the work that has been done over the past years by all of you and other colleagues of us. I think it is fair to say that for the first time I felt as if I were observing at a national facility (and I mean that in a positive way...) in terms of the overall efficiency, reliability, and in many ways also quality of the data. Clearly we have a way to go in instrumentation, and we should not lose focus on that effort. But the improvements compared to a few years ago are impressive, and I had not fully appreciated how effective these have been. If I can mention a few: the ease to use SPICAM and the clever implementation to take twilight flats in a very efficient and quick way, the slitviewer on DIS which will soon be further improved, the very quick selection and setup of guide stars, the good image quality at times of good seeing (one can easily imagine how much further closed loop focus/guiding would take us), and the overall reliability of the system, in spite of ongoing concerns about outdated and overly complex computer systems. I am sure that all of you have been aware of these improvements as they have occurred over the past years, but they could hardly appear more impressive than to one who had been too far away from the telescope for too long. Rene Walterbos APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 457 in the apo35-general archive. 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