Observing Log for Night 129  (July 7,1997  UT)

Observer: J. Dembicky

Weather Conditions: Sunset (19:30) - Clouds to the E & S and almost at zenith
                                     clearing in the W.  dissapating "puffy"
                                     clouds to the N.  Look like they are 
                                     thinning out and moving to the NE. 
                                     Lots of clouds to the ESE (70 deg alt.)
                                     Haze to W. Will do twilight flats in
                                     morning.
                             20:25 - Clouds E (35 deg alt.) with lightning
                                     (impressive). A few small clouds overhead
                                     and more towards N.  Haze in valley & W. 
                                     Clouds moving NE.
                             20:57 - Clear
                             21:56 - Clear overhead, clouds N & low S & E.
                             22:22 - Becoming cloudy in K & H bands
                             22:36 - K & H bands have stablized again.
                             22:51 - N - Clouds, W - Clouds/thick haze,
                                     S - Clouds, E - Clouds, NE and
                                     overhead - Clear (probably not for long)
                             23:54 - Clear (finally)
                             00:59 - Clear 
                             02:02 - Clear
                             02:57 - Clear (clouds maybe N) Clouds low E & S
                             03:59 - Clear
                             04:50 - Clear, Clouds to NE and low in S.

Eyeball quality estimates: Sunset - partly cloudy
                            20:25 - Clearing (not photometric)
                            20:57 - Photometric
                            21:56 - probably photometric, clouds on horizon.
                            22:22 - There HERE!!! (Clouds) not photometric
                            22:30 - Clouds coming in from N.
                            22:36 - Seems better in the area the telescope
                                    is pointing. (may change though)
                            23:54 - photometric
                            00:59 - Stars twinkling (probably photometric)
                            02:02 - Clear
                            02:57 - Photometric
                            03:59 - Photometric                     

Notes: Moved the plate that the dome drive motor rests on.  Looked as if it 
       was coming off.  Need to keep an eye on it.  TCS computer got confused
       after the operation (don't think the two were related).  Would not
       reverse the dome direction to stow dome (stowed 180 deg. off).  
       Rebooted TCS computer to fix problem.

       i2mass lock up. check to see if tile #13826 was scanned.  I think it 
       may have been written over due to reboot.


MST   Scan    Comment
17:02         ct= -192 (all)
17:14  001    Dark frames
20:19  002    tt=20.6 t=21.4 humid=30 Bkgnd= 300,1440,3470
              Sky is cloudy E (up to 35 deg alt.) Small clouds to N and
              a few very small clouds overhead.  Haze to W. ct= -192(all)
20:29  008    Bkgnd= 210,1275,3400
20:39  014    Bkgnd= 140,1450,3540
20:46  015    tt=21.0 t=21.4 humid=30 Bkgnd= 150,1700,3650 
20:57         Sky is clear (storms in far E), clouds seem to have dissapated.
21:21  020    tt=21.2 t=21.1 humid=31 Bkgnd= 50,1500,3560
21:42  023    tt=21.1 t=21.0 humid=31 Bkgnd= 10,1400,3500
21:56         Sky is clear overhead, clouds in N, low in S and E.
22:11  027    Bkgnd= 60,1750,3600
22:17  028    Clouds are starting to come in from the N.  K band is jumping
              all over the place. (+/- 1000)
22:22         There HERE!!!! K & H bands are jumping all over the place
22:30         Clouds are coming in from the N.
22:36  040    Clouds in the area, but the sky seems OK where the telescope
              is pointing, That may change though!
22:43  041    tt=20.6 t=20.7 humid=33 
22:51         Sky conditions N - Clouds, W - Clouds/thick haze, S - Clouds
              E - Clouds, NE and overhead - Clear (probably not for long)
22:53  042    K band jumping again (+/- 500)
22:57  043    K band has settled down again.
23:11  045    tt=20.7 t=20.3 humid=36 Bkgnd= 70,1325,3125
23:36  048    Bkgnd= 80,1200,3080
23:54  051    Bkgnd= 55,1050,3150
              Skies have cleared again
00:05  052    tt=20.5 t=19.6 humid=36 Bkgnd= 50,925,3075
00:13  054    tt=20.2 t=19.5 humid=39 Bkgnd= 100,1275,3300
00:23  060    tt=20.1 t=19.1 humid=42 Bkgnd= 80,1400,3350
00:35  066    Bkgnd= 10,760,2890
00:41         tt=19.4 t=18.3 humid=45
00:41         i2mass computer stopped responding.  Rebooted.
              restarted on scan 66.  Don't know if didn't complete or 
              went to the next one, may want to investigate.
              I think it might have lost tile #13826
00:59  068    tt=18.6 t=17.5 humid=48 Bkgnd= 25,760,2750
              Sky is clear (stars are twinkling) can feel the humidity.
              ct= -192 (all) 
01:19  071    Bkgnd= 45,950,2775
01:25  072    tt=18.1 t=17.2 humid=51
01:47  075    tt=17.6 t=16.9 humid=53 Bkgnd= 55,1050,2700
02:02         Sky is clear
02:13  079    tt=17.8 t=16.8 humid=56 Bkgnd= 30,1120,2800
02:24  085    Bkgnd= 50,1030,2675
02:33  091    tt=17.1 t=16.9 humid=53 Bkgnd= -5,775,2500
02:57         Sky is clear
03:05  095    tt=16.9 t=16.8 humid=50 Bkgnd= -5,590,2405
03:24  098    tt=16.7 t=16.8 humid=49 Bkgnd= -10,820,2440
03:50  102    tt=16.5 t=16.6 humid=50 Bkgnd= 0,900,2440
03:59         Sky is clear 
04:17  109    tt=16.7 t=16.5 humid=52 Bkgnd= 40,1040,2550
04:21  111    Bkgnd=25,800,2440
04:31  117    tt=16.3 t=16.6 humid=54 ct= -192 (all)
              Twilight Flats RA=233000.0 Dec +310000.0              
05:51         filled camera with LN2 (solenoid, short hose) 10 mins.