APO 3.5-m Users Committee Phonecon, 12/10/07 Attending: Suzanne Hawley, Bruce Gillespie, Scott Anderson, Ed Turner (for Michael Strauss), Remy Indebetouw, John Bally, Al Harper, Jon Holtzman, Russet McMillan Absent: Jon Fulbright, Mark Klaene, Michael Strauss Minutes taken by Bruce Gillespie ********************************** User feedback, comments from institutional representatives: Princeton (Turner) - Ed said that he didn't have any user feedback to report. UVa (Indebetouw) - Remy said the Virginia users are happy with their recent observing runs. UW (Anderson) - Scott had nothing new to report from the user side. CU (Bally) - John had no new user feedback to report. JHU (Fulbright) - No report. NMSU (Holtzman) - Jon had no user feedback about recent observing. UChicago (Harper) - Al reported that Chicago users had recently had good observing runs. ********************************** Discussion of telescope/instruments report - Gillespie: The report is given below. Bruce walked through the highlights, to which there was no substantive discussion: ************************* 3.5-m Telescope, Instruments, and CIF Projects Highlights, 11/15/07 through 12/05/07 Mark Klaene & Bruce Gillespie 0) Overview Sporadic winter weather has finally started to move in, mostly in the form of occasional rain, near-freezing temperatures, and wind. Observing-time losses due to weather increased slightly over the previous month, but overall the skies have been generally usable for observing. The site is preparing for the holiday break when much of the day staff will be on leave or standby status. SDSS-III construction continued at a reasonable pace without interference to nighttime observing. 1) Telescope We are optimistic that recent problems with tertiary rotation may have finally been solved. After extensive diagnostic effort, it was discovered that a scale bit in the tertiary rotation controller was not being correctly reset by an electrical jumper. Since this problem was found and corrected, there has been no further misbehavior of the tertiary rotation system. 2) Instruments DIS, SPIcam, and the echelle have all operated smoothly throughout the period, with no reported problems. The DIS spare Cryotiger compressor will be repaired and returned to the site by mid-January. The performance of the NIC-FPS ion pump has returned to nominal levels during the past month; the ion pump is being monitored with no near- term action currently planned. Also for NIC-FPS, CU scientists suspect they may know the cause of the increased detector noise that manifested since the upgrade to 16-channel read capability, and are fabricating a new fan-out board that would be installed next summer. NIC-FPS etalon testing continues towards reaching the requisite plate parallelism. The new focal reducer for Agile has been AR-coated and reinstalled in the instrument. Agile characterization tests were weathered out and a retry is planned for the next available opportunity. The visiting instruments (CorMASS, GFP, and APOLLO) are all operational. 3) CIF projects The designs for Agile field rotation and its move to TR2 port are nearly complete. ALso, good progress was made on the new axis controller for the instrument rotation axis--the system is currently undergoing operational testing at night. ********************************** NIC-FPS status - Bally: John talked about the problems with the NIC-FPS etalon, namely difficulties in obtaining plate parallelism. Corey Wood will be coming to APO to test the etalon with an artificial star. One possible cause of the problems may be related to the length of cable runs to the instrument. Also, a new, better shielded, fan-out board for the detector is being fabricated and will be installed the next time the instrument dewar is opened, with the hope of reducing read noise. The coronagraphic mode is now working, and uses new masks. There is a general problem with residual images when bright objects are observed; the residual images take ~hours to clear from the detector. It may be advisable for programs that have bright target objects to take these observations at the end of the night, although this would add a burdensome constraint to telescope scheduling. Al Harper suggested that experiments could be undertaken to mitigate the residual image problem, and that other groups that are using the Rockwell RG series detectors (e.g., the JWST group at GSFC) may have already found workarounds. John also said that a new "random" dither pattern (+/- 4 or 5 arcseconds) is highly recommended. It is unclear if this is currently supported within TUI. ACTION: User Committee members should find out if their NIC-FPS users are having problems with residual images caused by bright targets. ********************************** Time trades with WIYN - Hawley: Suzanne reminded us that she has been working with George Jacoby to arrange for time-swapping between WIYN and our 3.5-meter telescope. WIYN may have its One-Degree Imager (ODI) coming on line in the next year or two which would be a unique capability that we don't offer. The WIYN users appear to be most interested in using DIS. Anyone interested in access to WIYN should get in touch with Suzanne. The time trades would begin in about six to eight months. ********************************** User documentation - Hawley/Holtzman: Jon said that he is still taking user feedback on the new instrumentation web pages. The link to the new pages will be the default in the next month or so; the old pages will be archived and their links kept. ********************************** Miscellaneous: Ed Turner thanked the users who provided input to him regarding the reappointment of Suzanne as Director of the 3.5-m telescope. The ARC Board of Governors was pleased that Suzanne accepted the reappointment offer. Suzanne mentioned that an NMSU grad student has begun Observing Specialist training. The idea is that this person would be available for emergency fill-in situations on short notice. ********************************** [open from previous months]: ACTION: Committee members to look at the new user webpages, and report back to Jon Holtzman and Gabrelle Saurage suggestions for content and organization. STATUS: Open, Jon and Gabrelle waiting for more feedback. ACTION: John Bally will write a section with figures on Fowler sampling for inclusion in the NIC-FPS user documentation. STATUS: Open. [new actions from this month]: ACTION: User Committee members should find out if their NIC-FPS users are having problems with residual images caused by bright targets. ********************************** Next meeting: The next Users Committee phonecon will be on Monday, 14 January, at 8:30 AM Pacific Time. The agenda and other materials will be sent to the committee members during the preceding week. APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 1080 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO