David's Astronomy Pages
Notes - Session 849 (2021-01-12)

 
Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
 
Bullet Operational Issues
  - Critical Issues (0),  Major Issues (0),  Minor Issues (2),  Continuous Improvement (3)
Bullet Images from 2021-01-12 >>
Bullet Cloud Sensor Anomaly - low clarity ("cloud") values from a clear sky (17:15 to 17:40)
2021-01-15
Bullet Pulsar Dome - Shutter Chain Adjustments

Session Aims & Highlights (2021-01-12)

Main aims

  1. Targets. Acquire images of a selection of variable stars, nearby stars, comets and deep sky targets as allowed by conditions.

Equipment & Software

Highlights

Summary Plots & Logs

Observing Plan
Image
  
Observing Result
Image
   
Dome & Scope Slewing Performance
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Slew/Centering Performance
Image
  
Guiding Performance
Image
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Sky Conditions (Locate Frames)
Data for second part of night is erronous as Observatory shutter was unknowingly closed
Image
Chart unavailable for this session
  
Night Sky Summary Plot
Top axis: Sky Brightness at Zenith (in ADU/s)
Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)
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Pre-Session Weather Forecast (API data from darksky.net)
Pre-Session Weather forecast showed initial snow showers followed by slight clearing (85-91% cloud cover),
followed by overcast skies,  with possible sleet/snow showers moving to later to rain showers
as temperatures rose from -2 degC at dusk to 4 degC at dawn
Wind calm/light in first part of night, but strengthening later reached 17-19 mph by dawn.

In the event skies were very clear from dusk to 22:30 before clouding over for the remainder of the night with
prolonged rain shower at rain shower at 02:30-03:15.
Minumum Temperature of -4 degC at 22:00 before warming later in night under cloud.
Winds relatively light in first half of night, but strengthening towards dawn.
Image
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Session Event Log
Time     Event Detail
17:55:30 Session Monitoring AutoStart monitoring for Live Session opportunity starting between 17:55 & 06:32
17:55:34 Session AutoStarting Session autostarting (17:55)
17:56:04 Session Created Live Session Created (2021-01-12 S00849, ImageSaveNum: 849001)
17:56:07   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
17:58:04   Services Started Observatory Services started
17:58:12 Observatory (Auto) Observatory placed in Fully-Automated Mode
17:58:15 Session Pending Session pending (2021-01-12)
17:58:17 Session Initiating Session initiating (2021-01-12)
17:58:19   Plan Requested Observing Plan requested from AstroPlan (1.19.1)
17:58:50   Plan Loaded Observing Plan loaded to queue (2021-01-12 V1 BEST PLAN, Plan ID: 584)
17:59:02   Camera1 Connected SBIG Camera Connected (set point -25°C)
17:59:08   Telescope Connected Telescope Connected (TheSky6)
17:59:18 Session Equilibration Session ready for dome & camera equilibration
18:01:00   Dome Opened Dome opened (opening time 45s)
18:01:15 Session Running Session running
18:01:18   Queue Started Observing Queue started (38 targets selected)
18:02:28       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:04:53       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
18:06:41       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
18:06:43       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
18:08:51       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
18:10:37       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
18:10:52       Focusing Checked Foc2 Focusing Check Succeeded
18:13:15     Target Started (1/38) Target started (1/38, GCVS RX And)
18:16:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:18:15       Focusing Completed Foc1 AutoFocus Completed (Profile No 3)
18:20:48     Target Completed Target completed (1/38, GCVS RX And)
18:21:35     Target Started (2/38) Target started (2/38, UGC 1436 w/SN2021nv)
18:24:34       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:26:36       Focusing Completed Foc1 AutoFocus Completed (Profile No 4)
18:42:39     Target Completed Target completed (2/38, UGC 1436 w/SN2021nv)
18:43:27     Target Started (3/38) Target started (3/38, GCVS TT Ari)
18:44:44 Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Shutter)
18:44:46   HardSuspend Called Hard Suspend is called due to Critical Conditions (cloud)
18:45:02     Target Aborted (3/38) Target aborted (3/38, GCVS TT Ari) due to cloud
18:45:04   Queue Paused Queue paused for Session Suspension
18:45:06 Session Suspended Session suspended
18:45:49   Dome Closed Dome closed (closing time 45s)
18:54:38     Target Cancelled Target cancelled (3/38, GCVS TT Ari) due to cloud
19:03:21 Session Resuming Session resuming
19:04:06   Dome Opened Dome opened (opening time 45s)
19:04:08 Session Running Session running
19:04:10     Target Started (4/38) Target started (4/38, UGC 2528 w/AT2020adnx)
19:04:12   Queue Resumed Observing Queue resumed
19:20:33     Target Completed Target partially completed (4/38, UGC 2528 w/AT2020adnx)
19:20:35     Target Started (5/38) Target started (5/38, GCVS GK Per)
19:23:16       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:25:08       Focusing Completed Foc1 AutoFocus Completed (Profile No 5)
19:28:02     Target Completed Target completed (5/38, GCVS GK Per)
19:28:04     Target Started (6/38) Target started (6/38, UGC 784 w/SN2021pc)
19:31:07       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:33:14       Focusing Completed Foc1 AutoFocus Completed (Profile No 6)
19:49:11     Target Completed Target completed (6/38, UGC 784 w/SN2021pc)
19:49:13     Target Started (7/38) Target started (7/38, UGCA 24)
19:51:43       Focusing Skipped Foc1 focusing skipped - unable to find a star (TCF-S)
20:08:55     Target Completed Target completed (7/38, UGCA 24)
20:10:02   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (reducing clarity)
20:10:04 Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Shutter)
20:10:06   HardSuspend Called Hard Suspend is called due to Critical Conditions (cloud)
20:10:08   Queue Paused Queue pausing for Session Suspension
20:10:10 Session Suspended Session suspended
20:10:57   Dome Closed Dome closed (closing time 50s)
20:20:08   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
20:23:28 Session Resuming Session resuming
20:24:13   Dome Opened Dome opened (opening time 45s)
20:24:15 Session Running Session running
20:24:17   Queue Resumed Observing Queue resumed
20:24:19     Target Started (8/38) Target started (8/38, NGC 1110)
20:36:15     Target Completed Target partially completed (8/38, NGC 1110)
20:36:17     Target Started (9/38) Target started (9/38, UGCA 80)
20:39:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:41:49       Focusing Completed Foc1 AutoFocus Completed (Profile No 7)
20:57:27     Target Completed Target completed (9/38, UGCA 80)
20:57:30     Target Started (10/38) Target started (10/38, UGCA 211)
21:00:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:02:57       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
21:08:52   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
21:09:22   SoftSuspend Cancelled Soft Suspend is cancelled due to Improved Conditions
21:18:36     Target Completed Target completed (10/38, UGCA 211)
21:18:38     Target Started (11/38) Target started (11/38, 398P/Boattini)
21:21:04   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
21:22:20       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:22:29 Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Shutter)
21:22:31   HardSuspend Called Hard Suspend is called due to Critical Conditions (cloud)
21:22:40       Focusing Aborted Foc1 Focusing Aborted
21:22:42     Target Aborted (11/38) Target aborted (11/38, 398P/Boattini) due to cloud
21:22:44   Queue Paused Queue paused for Session Suspension
21:22:47 Session Suspended Session suspended
21:23:34   Dome Closed Dome closed (closing time 49s)
21:31:16     Target Cancelled Target cancelled (11/38, 398P/Boattini) due to rain
21:42:20     Target Cancelled Target cancelled (12/38, GCVS RR Tau) due to cloud
21:42:51   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
22:02:05     Target Cancelled Target cancelled (13/38, GCVS CM Tau) due to cloud
22:02:52   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
22:16:27     Target Cancelled Target cancelled (14/38, Nova Per 2020 w/AT2020abap) due to cloud
22:22:54   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
22:45:19     Target Cancelled Target cancelled (15/38, UGCA 105) due to rain
23:09:41     Target Cancelled Target cancelled (16/38, NGC 4414 w/SN2021J) due to cloud
23:32:03     Target Cancelled Target cancelled (17/38, UGCA 140) due to other condition
23:35:21 Session Resuming Session resuming
23:36:06   Dome Opened Dome opened (opening time 45s)
23:36:08 Session Running Session running
23:36:10     Target Started (18/38) Target started (18/38, UGC 4704)
23:36:12   Queue Resumed Observing Queue resumed
23:38:19       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:40:22       Focusing Completed Foc1 AutoFocus Completed (Profile No 10)
23:56:23     Target Completed Target completed (18/38, UGC 4704)
23:57:25     Target Started (19/38) Target started (19/38, GCVS U Gem)
23:59:35       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:01:50       Focusing Completed Foc1 AutoFocus Completed (Profile No 11)
00:04:34     Target Completed Target completed (19/38, GCVS U Gem)
00:06:58     Target Started (20/38) Target started (20/38, NGC 2782 w/SN2020scc)
00:07:29   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (reducing clarity)
00:07:31 Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Shutter)
00:07:33   HardSuspend Called Hard Suspend is called due to Critical Conditions (cloud)
00:07:36   SoftSuspend Cancelled Soft Suspend is cancelled due to Improved Conditions
00:07:38     Target Aborted (20/38) Target aborted (20/38, NGC 2782 w/SN2020scc) due to cloud
00:07:40   Queue Paused Queue paused for Session Suspension
00:07:42 Session Suspended Session suspended
00:08:29   Dome Closed Dome closed (closing time 50s)
00:26:20     Target Cancelled Target cancelled (20/38, NGC 2782 w/SN2020scc) due to cloud
00:40:17 Session Resuming Session resuming
00:41:02   Dome Opened Dome opened (opening time 45s)
00:41:04 Session Running Session running
00:41:06     Target Started (21/38) Target started (21/38, UGC 5341)
00:41:08   Queue Resumed Observing Queue resumed
00:54:24     Target Completed Target partially completed (21/38, UGC 5341)
00:54:26     Target Started (22/38) Target started (22/38, UGCA 200)
00:57:16       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-S)
01:14:50     Target Completed Target completed (22/38, UGCA 200)
01:14:52     Target Started (23/38) Target started (23/38, UGCA 217)
01:17:38       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-S)
01:35:17     Target Completed Target completed (23/38, UGCA 217)
01:36:26     Target Started (24/38) Target started (24/38, UGCA 291)
01:39:42       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:41:40       Focusing Completed Foc1 AutoFocus Completed (Profile No 12)
01:57:14   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
01:57:30     Target Completed Target completed (24/38, UGCA 291)
01:57:32   Queue Paused Queue paused for Session Suspension
01:57:34 Session Suspended Session suspended
01:58:24   Dome Closed Dome closed (closing time 50s)
02:07:35   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
02:16:17     Target Cancelled Target cancelled (25/38, Frosty Leo Nebula) due to threat of rain
02:27:37   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
02:37:09     Target Cancelled Target cancelled (26/38, UGC 5164) due to cloud
02:37:38   Camera1 SetPoint -25°C SBIG Camera Set Point Temperature Updated (new set point -25°C)
02:59:31     Target Cancelled Target cancelled (27/38, UGC 5760 w/SN2020zoq) due to cloud
03:07:41   Camera1 SetPoint -20°C SBIG Camera Set Point Temperature Updated (new set point -20°C)
03:21:53     Target Cancelled Target cancelled (28/38, NGC 4454 w/SN2020abgq) due to cloud
03:44:15     Target Cancelled Target cancelled (29/38, NGC 4731) due to cloud
04:06:37     Target Cancelled Target cancelled (30/38, UGC 7607) due to cloud
04:28:59     Target Cancelled Target cancelled (31/38, UGCA 304) due to cloud
04:51:21     Target Cancelled Target cancelled (32/38, UGC 8067) due to cloud
05:13:43     Target Cancelled Target cancelled (33/38, UGCA 279) due to cloud
05:31:00     Target Cancelled Target cancelled (34/38, M85) due to cloud
05:46:05 Session Resuming Session resuming
05:46:50   Dome Opened Dome opened (opening time 45s)
05:46:52 Session Running Session running
05:46:54     Target Started (35/38) Target started (35/38, NGC 5579)
05:46:56   Queue Resumed Observing Queue resumed
05:56:58     Target Completed Target partially completed (35/38, NGC 5579)
05:57:01     Target Started (36/38) Target started (36/38, UGC 6930 w/SN2020rcq)
06:00:26   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
06:00:48     Target Failed Target failed due to cloud (36/38, UGC 6930 w/SN2020rcq)
06:00:50   Queue Paused Queue paused for Session Suspension
06:00:52 Session Suspended Session suspended
06:01:41   Dome Closed Dome closed (closing time 50s)
06:07:47 Session Resuming Session resuming
06:08:32   Dome Opened Dome opened (opening time 45s)
06:08:34 Session Running Session running
06:08:36   Queue Resumed Observing Queue resumed
06:08:38     Target Started (36/38) Target started (36/38, UGC 6930 w/SN2020rcq)
06:15:39     Target Completed Target partially completed (36/38, UGC 6930 w/SN2020rcq)
06:15:41     Target Started (37/38) Target started (37/38, UGCA 259)
06:18:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
06:21:04       Focusing Completed Foc1 AutoFocus Completed (Profile No 13)
06:37:05     Target Completed Target completed (37/38, UGCA 259)
06:37:07     Target Started (38/38) Target started (38/38, MCG +6-30-84 w/SN2021K)
06:40:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
06:42:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 14)
06:58:01     Target Completed Target completed (38/38, MCG +6-30-84 w/SN2021K)
06:58:04   Queue Completed Job Queue completed
06:58:07 Session Closing Session closing
06:59:02   Dome Closed Dome closed (closing time 50s)
07:00:06   Dome Parked Dome parked (parking time 57s), Az: 90.0 deg
07:00:40   Telescope Parked Telescope parked (parking time 32s)
07:01:10   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
07:01:59   Services Stopped Night Services stopped
07:02:01 Session Housekeeping Housekeeping Started (Cleanup FITS, Create Fits Summary, Transfer Files)
07:02:12 Session Finished Session Finished
 
 
Session Alerts
Time     Alert Detail
-- No Alerts                --                              
 

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Operational Issues (2021-01-12 S849)

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Critical Issues

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Minor Issues

Continuous Improvement

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Cloud Sensor Anomaly - low clarity ("cloud") values from a clear sky (17:15 to 17:40)

A plan to start the night's observing session shortly after dusk (and after a rain shower had passed through) were thwarted as CloudSensor Clarity reading were only 15-20, which is normally taken to represent Cloud with potential for rain,  and opening of the Observatory Dome was prevented by the Observatory Control/Protection System.  This was despite the fact that the sky was most definately clear and shown by the AllSky Camera view, which showed absence of cloud and plenty of stars.

 It was initially thought that a bird might have come to rest on the Cloud Sensor (as this was likely explanation of some previous sudden changes in Clarity value), but checking outside with a torch didn't reveal any bird or transient object on the CloudSensor Unit.

It had been very recently raining/sleeting which had frozen on contact with the ground, and this might have formed a covering on the Cloud Sensor or otherwise temporarily affected the CloudSensor unit.  Clarity values gradually increased over course of 15 mins, but only began to return to expected values a point some 25-30 minutes after rain/sleet stopped.  After that cloudSensor readings responded normally to lthe evel of cloud cover for the remainder of the night.  

Examining CloudSensor data records shows that the CloudSensor's internal temperature cooled from 14.2°C before the freezing rain event to 11.3°C when rain stopped (a 3°C decrease in temperature).  The Sensor's interval temperature remained at around 11.3 to 11.2°C until around 17:40 when temperature increased to 13.0°C over a 5 minute period before climbing to 13.8 over a further 10 minute period. The sharp temperature change at 17:40 to 17:45 corresponds with the end of anomalous clarity values, suggest that the anomaly is driven by an unsual ambient/sensor temperatures.    The extent to which this also corresponded with an atmospheric temperature effect is unknown.

Given that the issue was of only short duration and evidently rare and one that increases safety marigins by keeping the shutter closed it was decided to close the issue after documenting it for future awareness & reference.

Graphs and an examples AllSky Image for the period of anomalous cloud sensor readings are shown below.

  
Anomaly in Cloud Sensor Data between 17:15 and 17:40
Clarity Values from Cloud Sensor 15-20 indicate cloud, but AllSky Star Count and AllSky Image indicate clear sky
The time period was proceeded a short interval of freezing rain or sleet at 16:55 to 17:05
   Image
  
   Image
 
AllSky Image at 17:32
(taken during period with Anomalous Cloud Sensor Data (17:15 to 17:40)
The Cloud Sensor indicates Cloud , but the sky is definitively Clear (see the abundance of stars across the whole sky)
Image 
 
  
Graph showing that CloudSensor Internal Temperature being affected by Freezing Rain Event
for period of some 40 minutes after rain had stopped.
Image

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2021-01-15


Pulsar Dome - Shutter Chain Adjustments

Following an issue with shutter opening in Session S847 (2021-01-08)  (opening failed after 10-27s with ShutterStatus Error=5  and opening stutters/jumps awkwardly when chain bolt goes over guide wheels) and some advice from Pulsar Observations, a couple for adjustments were made to the Observatory's Shutter Chain today (2021-01-15).

Photo showing previous chain bolt spacing
(2 nuts + 1 washer)
(photo taken 2021-01-09)
  Photo showing new reduced chain bolt spacing
(1 nut + 3 washers)
(photo taken 2021-01-15)
Image    Image
  
Photo showing previous slack
 in shutter chain
(photo taken 2021-01-09)
  Photo showing shutter chain post-tightening
(slack removed by taking out one link in chain)
(photo taken 2021-01-15)
Image    Image
  
Photo showing upper pulley wheel with
tightened chain and reduced chain bolt spacing
(photo taken 2021-01-15) 
  Photo showing shutter chain
after tightening
(photo taken 2021-01-15)
 Image    Image
  
  

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