Date: Sun, 03 Oct 1999 08:37:30 -0600 From: "s. a. snedden" Subject: 2.5m obslog 19991002 (MJD 51454) --------------779790F4A0C0DC5C11899065 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Saturday October 2, 1999 Apache Point Observatory SDSS 2.5m Observing Log (MJD 51454) Observing Team: Steph Snedden (APO) Scot Kleinmann (APO) Connie Rockosi (UC) Jim Gunn (PU) Scott Burles (UC) Robert Lupton (PU) Tonight was to be devoted to spectroscopy. By the end of the night we succeeded in successfully getting spectra only for plate 187 (cartridge 4). We did acquire one fifteen minute exposure on plate 191, but the image quality was quite bad (see next paragraph). We installed the engineering camera to check collimation, and will need to finish this tomorrow evening, so please leave the engineering camera on the telescope. We got a late start because the primary mirror oscillation problem from last night recurred while we were getting set up and doing the pre-flight check. After many phone calls to various support staff, Jim Gunn reached and consulted with York Brown. At 20:20 Jim backed off the proportional gain trimpots on the outer loop, one turn for each of the three axial actuators. The oscillations appeared to be much reduced, if not stopped. Later, however, the images taken while guiding on the second plate (191 on cartridge 2) were very poor...blurry and oblong, for the most part. At first, we believed this was a collimation problem so we installed the engineering camera and started to check this. The out-of-focus star images images appeared to be coma-free, so perhaps the blurry images seen earlier were caused by an oscillation of the primary. We are not sure. NOTE: MIRROR OSCILLATIONS WERE SEEN (BASED ON PRESSURE VARIATIONS OF 41-45 PSI) DURING SHUTDOWN. PRIMARY WAS RETURNED TO REVERSE AXIAL LIMITS. Counterweights for 2 spectrographs, cartridge, corrector and two full dewars: 315 V Counterweights for engineering camera, spectrographs and two half full dewars: 270 V Focus for spectrographs: 1250 Focus for engineering camera near -3100 DIMM Seeing: 1.5-2.0", degrading to about 2.5" near midnight. setmir values: 0, -27.4, 7.8, 427, 1495 galils: 2797, -1543, 1346, 10062, 7365, 7063 ______________ Problems: (problem reports to be filed) 1) Primary oscillations -- see above 2) 21:00.. guide camera didn't respond. The fibers had been left unconnected when the cartridge was installed. 3) At about 21:15 the MCP had to be re-booted. Azimuth fiducial 33 was not found when resetting fiducials. 32 and 34 were read without trouble. Only 33 was a problem. 4) 21:30..Telescope stopped moving in azimuth. This was a small move to our spectroscopy field from a nearby FK5 star. Reinitializing the axes solved the problem. 5) 00:20.. Azimuth motion stopped when an extension cord caught under the doghouse paddle. We removed the cord and reinitialized the axes. 6) From about 02:00 until dawn we worked on collimation. The TCC started to run very slowly...too many sessions? It also took a great deal of time to check mirror positions and change focus with t_collimate not running. We also lost our azimuth fiducial toward morning twilight. Weather: Mostly clear with SW, then W winds at 10-15 mph. RH varied from 25-30%. Dust particle density stayed below 70 particles/ft^3. The temperature stayed in the high 50's. Steph & Scot --------------779790F4A0C0DC5C11899065 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Saturday October 2, 1999 Apache Point Observatory SDSS 2.5m Observing Log (MJD 51454) Observing Team: Steph Snedden (APO) Scot Kleinmann (APO) Connie Rockosi (UC) Jim Gunn (PU) Scott Burles (UC) Robert Lupton (PU) Tonight was to be devoted to spectroscopy. By the end of the night we succeeded in successfully getting spectra only for plate 187 (cartridge 4). We did acquire one fifteen minute exposure on plate 191, but the image quality was quite bad (see next paragraph). We installed the engineering camera to check collimation, and will need to finish this tomorrow evening, so please leave the engineering camera on the telescope. We got a late start because the primary mirror oscillation problem from last night recurred while we were getting set up and doing the pre-flight check. After many phone calls to various support staff, Jim Gunn reached and consulted with York Brown. At 20:20 Jim backed off the proportional gain trimpots on the outer loop, one turn for each of the three axial actuators. The oscillations appeared to be much reduced, if not stopped. Later, however, the images taken while guiding on the second plate (191 on cartridge 2) were very poor...blurry and oblong, for the most part. At first, we believed this was a collimation problem so we installed the engineering camera and started to check this. The out-of-focus star images images appeared to be coma-free, so perhaps the blurry images seen earlier were caused by an oscillation of the primary. We are not sure. NOTE: MIRROR OSCILLATIONS WERE SEEN (BASED ON PRESSURE VARIATIONS OF 41-45 PSI) DURING SHUTDOWN. PRIMARY WAS RETURNED TO REVERSE AXIAL LIMITS. Counterweights for 2 spectrographs, cartridge, corrector and two full dewars: 315 V Counterweights for engineering camera, spectrographs and two half full dewars: 270 V Focus for spectrographs: 1250 Focus for engineering camera near -3100 DIMM Seeing: 1.5-2.0", degrading to about 2.5" near midnight. setmir values: 0, -27.4, 7.8, 427, 1495 galils: 2797, -1543, 1346, 10062, 7365, 7063 ______________ Problems: (problem reports to be filed) 1) Primary oscillations -- see above 2) 21:00.. guide camera didn't respond. The fibers had been left unconnected when the cartridge was installed. 3) At about 21:15 the MCP had to be re-booted. Azimuth fiducial 33 was not found when resetting fiducials. 32 and 34 were read without trouble. Only 33 was a problem. 4) 21:30..Telescope stopped moving in azimuth. This was a small move to our spectroscopy field from a nearby FK5 star. Reinitializing the axes solved the problem. 5) 00:20.. Azimuth motion stopped when an extension cord caught under the doghouse paddle. We removed the cord and reinitialized the axes. 6) From about 02:00 until dawn we worked on collimation. The TCC started to run very slowly...too many sessions? It also took a great deal of time to check mirror positions and change focus with t_collimate not running. We also lost our azimuth fiducial toward morning twilight. Weather: Mostly clear with SW, then W winds at 10-15 mph. RH varied from 25-30%. Dust particle density stayed below 70 particles/ft^3. The temperature stayed in the high 50's. Steph & Scot --------------779790F4A0C0DC5C11899065--