David's Astronomy Pages
Notes - Session 928 (2021-10-25)

 
Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
 
Bullet Operational Issues
  - Critical Issues (0),  Major Issues (2),  Minor Issues (7),  Small Defects (1),  Continuous Improvement (13)
 
Bullet Images from 2021-10-25 >>         [ Local Files >> ]
Bullet LX200 - Proposed Polar Alignment Change

Session Aims & Highlights (2021-10-25)

Main aims

  1. AstroAllSky. Perform a live test of AstroAllSky 3.12.7 with new TP2 handing
  2. Targets.  Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by time & conditions.
  3. Guiding Performance. Make further guiding runs with the recently installed new Dec Motor Unit and following a couple of changes since previous S927 session

Equipment & Software

Highlights

Notes:


  Summary Plots & Logs

Observing Plan
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Observing Result
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Dome & Scope Slewing Performance
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Slew/Centering Performance
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Guiding Performance
Image
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Sky Conditions (Locate Frames)
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Night Sky Summary Plot
Top axis: Sky Brightness at Zenith (in ADU/s)
Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)

Gaps in plot are due to a number of AstroAllSky program restarts to install
new program builds that were attempting to fix a bug associated with
sending Cloud/Sky results back to the Observatory computer.
Image   
  
Actual Weather vs Pre-Session Weather Forecast
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Session Event Log
Time     Event Detail
18:40:22 Session Monitoring AutoStart monitoring for Live Session opportunity between 18:40 & 06:01
18:40:25   AutoStart Delayed Session delayed due to too few stars
18:54:01 Session AutoStarting Session autostarting (18:54)
18:54:31 Session Created Live Session Created (2021-10-25 S00928, ImageSaveNum: 928001)
18:54:34   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
18:56:15   Services Started Observatory Services started
18:56:23 Observatory (Auto) Observatory placed in Fully-Automated Mode
18:56:26 Session Pending Session pending (2021-10-25)
18:56:28 Session Initiating Session initiating (2021-10-25)
18:56:30   Plan Requested Observing Plan requested from AstroPlan (1.26)
18:59:03   Plan Loaded Observing Plan loaded to queue (, Plan ID: 679)
18:59:27   Camera1 Connected SBIG Camera Connected (set point -15°C)
18:59:33   Telescope Connected Telescope Connected (TheSky6)
19:00:03 Session Equilibration Session ready for dome & camera equilibration
19:00:48   Dome Opened Dome opened (opening time 45s)
19:00:50 Session Running Session running
19:00:53   Queue Started Observing Queue started (45 targets selected)
19:00:54     Target Started (NrZen) Target started (Focus Field 20, HIP 98535)
19:02:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:06:21       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide)
19:09:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
19:09:06       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
19:11:34       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
19:13:32       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
19:13:52     Target Completed Target completed (Focus Field 20, HIP 98535)
19:13:55     Target Started (1/45) Target started (1/45, Vega)
19:14:00     Target Failed Target failed due to aborted (1/45, Vega)
19:14:02   Queue Aborted Job Queue aborted
19:17:05   Automapping Started Automapping started (12 points planned)
19:20:00 Program Hung TheSky6 and CCDSoft programs hung whilst linking map point 3/12
19:20:43 Obs.Monitor Frozen Obs.Monitor appears to be frozen at around 19:20 in section Monitor TheSky6 Scope
19:26:08 Session Resumed Live Session Resumed (2021-10-25 S00928, ImageSaveNum: 928004)
19:26:34   Obs.Manager Started Obs.Manager started
19:26:36   Obs.Overseer Started Obs.Overseer started
19:26:40   Services Started Observatory Services started
19:26:50   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
19:28:35   Services Started Observatory Services started
19:28:52   Telescope Connected Telescope Connected (TheSky6)
19:29:29   Camera1 Connected SBIG Camera Connected (set point -15°C)
19:31:39   Automapping Started Automapping started (12 points planned)
19:47:50   Automapping Completed Automapping completed (12 points mapped out of 12 points)
19:50:41   Telescope Parked Telescope parked (parking time 71s)
19:50:56   Telescope State Scope parked Turn scope off. (Handbox)
19:51:16   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
19:52:48   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
19:54:21   Services Started Observatory Services started
19:54:52   Telescope Connected Telescope Connected (TheSky6)
19:56:40 Session Monitoring AutoStart monitoring for Live Session opportunity between 19:56 & 06:01
19:56:42 Observatory (AutoStart) Observatory placed in Auto-Start Mode
19:56:44 Session AutoStarting Session autostarting (19:56)
19:57:04   Services Started Observatory Services started
19:57:08 Observatory (Auto) Observatory placed in Fully-Automated Mode
19:57:12 Session Pending Session pending (2021-10-25)
19:57:14 Session Initiating Session initiating (2021-10-25)
19:57:31   Plan Loaded Observing Plan loaded to queue (, Plan ID: 679)
19:57:43   Camera1 Connected SBIG Camera Connected (set point -20°C)
19:57:49   Telescope Connected Telescope Connected (TheSky6)
19:58:13 Session Equilibration Session ready for dome & camera equilibration
19:58:15 Session Running Session running
19:58:18   Queue Started Observing Queue started (44 targets selected)
19:58:20     Target Missed (2/45) Target's time slot was missed (2/45, GCVS RR Lyr)
19:58:22     Target Missed (3/45) Target's time slot was missed (3/45, Vega)
19:58:24     Target Missed (4/45) Target's time slot was missed (4/45, 61 Cyg)
19:58:26     Target Started (5/45) Target started (5/45, NGC 6627 w/AT2021abkm)
20:10:10     Target Completed Target partially completed (5/45, NGC 6627 w/AT2021abkm)
20:10:13     Target Started (6/45) Target started (6/45, AT2021yel (CV))
20:13:59       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:15:50       Focusing Completed Foc1 AutoFocus Completed (Profile No 5)
20:22:24     Target Completed Target completed (6/45, AT2021yel (CV))
20:22:26     Target Started (7/45) Target started (7/45, AT2021zkf)
20:25:46       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:27:35       Focusing Completed Foc1 AutoFocus Completed (Profile No 6)
20:44:42     Target Completed Target completed (7/45, AT2021zkf)
20:44:44     Target Started (8/45) Target started (8/45, GCVS BL Lac)
20:48:20       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:50:44       Focusing Completed Foc1 AutoFocus Completed (Profile No 7)
20:55:13     Target Completed Target completed (8/45, GCVS BL Lac)
20:55:15     Target Started (9/45) Target started (9/45, UGC 12188 w/SN2021ucg)
21:00:46       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:02:58       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
21:16:22     Target Completed Target partially completed (9/45, UGC 12188 w/SN2021ucg)
21:16:25     Target Started (10/45) Target started (10/45, UGC 235 w/AT2021aazm)
21:19:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:21:29       Focusing Completed Foc1 AutoFocus Completed (Profile No 9)
21:38:01     Target Completed Target completed (10/45, UGC 235 w/AT2021aazm)
21:38:04     Target Started (11/45) Target started (11/45, WDS GRB 34)
21:40:30       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:42:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 10)
21:44:51     Target Completed Target completed (11/45, WDS GRB 34)
21:44:54     Target Started (12/45) Target started (12/45, GCVS RX And)
21:47:32       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:49:45       Focusing Completed Foc1 AutoFocus Completed (Profile No 11)
21:53:12     Target Completed Target completed (12/45, GCVS RX And)
21:53:14     Target Started (13/45) Target started (13/45, GCVS SS Cyg)
21:57:35       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:59:50       Focusing Completed Foc1 AutoFocus Completed (Profile No 12)
22:04:52     Target Completed Target completed (13/45, GCVS SS Cyg)
22:07:26     Target Started (14/45) Target started (14/45, GCVS EV Lac)
22:10:56       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:13:25       Focusing Completed Foc1 AutoFocus Completed (Profile No 13)
22:14:35   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
22:16:10     Target Completed Target completed (14/45, GCVS EV Lac)
22:16:12   Queue Paused Queue paused for Session Suspension
22:16:14 Session Suspended Session suspended
22:17:00   Dome Closed Dome closed (closing time 50s)
22:35:05     Target Cancelled Target cancelled (15/45, UGC 12354 w/SN2021tyw) due to cloud
22:46:15     Target Cancelled Target cancelled (16/45, GCVS HH And) due to cloud
22:57:12     Target Cancelled Target cancelled (17/45, AT2021yxa (CV)) due to cloud
23:09:35     Target Cancelled Target cancelled (18/45, AT2021vdq (CV)) due to cloud
23:19:08     Target Cancelled Target cancelled (19/45, GCVS Z And) due to cloud
23:30:15     Target Cancelled Target cancelled (20/45, AT2021abog (CV)) due to cloud
23:50:07     Target Cancelled Target cancelled (21/45, SN 2021yal) due to cloud
00:11:19     Target Cancelled Target cancelled (22/45, 67P/Churyumov-Gerasimenko) due to cloud
00:20:30     Target Cancelled Target cancelled (23/45, GCVS GK Per) due to cloud
00:30:45   Queue Aborted Job Queue aborted
00:31:03 User Intervention User request to close and finish session
00:31:05 Session Closing Session closing
00:31:07   Dome Closed Dome already closed (closed at 22:17, closing time 50s)
00:32:06   Dome Parked Dome parked (parking time 55s), Az: 90.0 deg
00:33:29   Telescope Parked Telescope parked (parking time 77s)
00:33:44   Telescope State Scope parked Turn scope off. (Handbox)
00:34:04   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
00:34:55   Services Stopped Night Services stopped
00:34:57 Session Housekeeping Housekeeping Started (Cleanup FITS, Create Fits Summary, Transfer Files)
00:35:03 Session Finished Session Finished
 
Session Alerts
Time     Alert Detail
19:21:13 Obs.Monitor Obs.Monitor appears to be frozen in section Monitor TheSky6 Scope (last cycle at 19:20:42)

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Operational Issues (2021-10-25, S928)

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Critical Issues

Major Issues

Minor Issues

Small Defects

Continuous Improvement

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LX200 - Proposed Polar Alignment Change

Given the LX200's continuing Dec Guiding issues it is proposed to minimise the effects of poor Dec guiding by improving the mount's polar alignment at some point shortly.

Recent TPoint Mapping run on 2021-10-19 show a total polar misalignment of  19.3 arc minutes [ MA +44" (+0.7'), ME: -1159" (-19.3') ]. The Polar Information collected was similar to that collected in 2020. The azimuthal misalignment is acceptable, but the altitude misalignment probably needs reducing regardless of the ongoing Dec Guiding Issue.  Polar axis should be lowered by ~ 18-19'  . A little misalignment will probably be kept just in case the current Dec Guiding Issues can eventually be overcome.

The visual representation of the proposed Polar Alignment change is shown in the following diagram.

Image

Post Re-Alignment

TPoint
Following the Polar Alignment change a new TPoint Mapping Run will need to be undertaken. If this can't be done immediately it might be feasible to adapt the existing T Point Model by fixing terms and changing the ME Term to 0.0 or a small negative number like  -60  (if 1' of misalignment is retained).   This doesn't remove the need for make a new TPoint Model from new mapping data.   This new model will be used to required to confirm the success of Polar Alignment Change made.

(Note:  due to either tube/fork flexures or an E/W tilt in the pier's mounting plate the use of Star Drift method for checking Polar Alignment has limitations. When trying to use the direction of star drift taken at the east & west sky points the Polar Alignment Information has previously been found to be ambiguous)

Comets
When Guiding on Comets and asteroids after the Polar Alignment Change the selection of  Dec Guide Mode for the guide run will need to consider the expected N/S direction of comet/asteroid motion.  Previously when Dec Guiding with a misaligned polar axis the rate of N/S motion of comets was generally less that rate of star drift and therefore selection of Dec Guid Mode has had to consider the comet direction of motion.  But in future with lower expected star drift the selection of Dec Guide Mode for Unidirectional guide will need to consider the comet/asteroid forecast direction of (N/S) motion.

Polar Alignment 2021 & 2020

Comparison of Polar Alignment Information from new mapping run (2021) with that from previous runs (2020) shows there has been no significant change in polar alignment between the two dates.   The moun's polar axis is fairly well aligned in azimuth (1.2 min error only), but has a misalignment in altitude of 19.5 mins.  

Polar Alignment Information from New Mapping Run (2021-10-19)
179 data points.
 Best TPoint Model 16 terms
 
 Image   
     
Polar Alignment Information from Earlier Mapping (2020-01-17)
155 data points.
 Best TPoint Model  - 16 terms
 Image   
     
Polar Alignment Information from Earlier Mapping  (2018-05-17)
121 data points.
 Alternate TPoint Model 8 terms
 
 Image   

 

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