David's Astronomy Pages Notes - Session 1352 (2025-08-26)

Notes (S1351)

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Notes (S1353)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (0),  Minor Issues (0),  Small Defects (2),  Continuous Improvement (4)
	- Figures (4)
	Images from 2025-08-26  >>

Session Aims & Highlights (2025-08-26)

Main aims

1. Targets.  Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by sky conditions and the relatively short night.
2. T CrB & Nova Ser 2025.  Acquire images of T CrB and the recently discovered  Nova Ser 2025
3. Short Exposure Testing. Carry out short exposure testing of NSV 14339 to understand & demonstrate S/N issues  that would present themselves if taking & stacking 2ms exposures of the Crab Nebula Pulsar.

 Equipment & Software

• 12" LX200 and ST-10XME
• 80mm APO and ZWO ASI 178MC
• TheSky6, CCDSoft5, DeviceHub 7.0.3 RC3.4694, MeadeGeneric 1.3.12.522 , UPB 1.5,  Pulsar Dome Firmware 1.51 & Driver 6.3.10
• Pegasus UPB & Motor Focus, TCF-S 6.0.6
• SharpCap 3.2, PHD2  2.6.13, Siril 1.0.6, deCONZ 1.18.2, ASCOM 7.0.3 RC3
• [ DomeLink 1.0 / 1.1 - not used ]
   
• AstroMain 3.77.9,  AstroPlan 1.43.12, AstroShCap 1.3.15, AstroGuard 1.11  (any new items or versions in bold)
  AstroMag 1.5.8, AstroVOE 1.15.1,  AstroSN 1.14,  AstroProtect 1.10.6,  AstroMove 1.16.2
  AstroWeather 1.27.9, AstroAllSky 3.24.4,  AstroObsCam 1.11.4 (not 1.11.5), AstroNorthCam 1.6.1, AstroLaunch 1.13.6

Highlights

• Targets. 19/21 planned  targets were successfully completed with one target partially completed. The remaining planned target (Z And) failed due to cloud.
• T CrB & Nova Ser 2025. Both targets were successfully acquired, along with NGC 5957 w/SN
• Short Exposure Testing. Short exposure testing of NSV 14339 (mag 11.7) was carried out using 100 x 0.12s frames and demonstrated that taking & stacking 2ms exposures of the Crab Nebula Pulsar (~ mag 16.5) wasn't going to be a feasible option.
• AstroNorthCam / Stars.  Star Count from NorthCam showed good data and a good correspondance with the star count from AllSky Camera.
• CCD Camera.  No issues with CCD Camera during session.
•  Dome. There was no issues opening/closing the shutter during the session. Dome closed and parked at end of session ok.

Notes

Summary Plots & Logs

Observing Plan

Observing Result

Dome & Scope Slewing Performance

Slew/Centering Performance

Guiding Performance

Sky Conditions (Locate Frames)

Night Sky Summary Plot Top axis: Sky Brightness at Zenith (in ADU/s) Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs) Note:  The NorthCam Star Count line is unreliable and should be ignored (The AstroNorthCam 'Find' Star method is producing many false positives from clouds)

Actual Weather vs Pre-Session Weather Forecast

Session Event Log

Time     Event Detail 18:16:45 Session Monitoring AutoStart monitoring for Live Session opportunity between 21:07 & 04:02 18:16:47   AutoStart Waiting AutoStart waiting till earliest start time at 21:07 21:08:01   AutoStart Delayed Session delayed due to cloud 22:03:26 Session AutoStarting Session autostarting (22:03) 22:03:38   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 22:03:53 Session Created Session Created (Live, 2025-08-26 S01352, ImageSaveNum: 1352001) 22:03:59   Scope Switched On Telescope Power has been switched on via UPB Switch 22:05:47   Services Started Observatory Services started 22:05:56 Observatory (Auto) Observatory placed in Fully-Automated Mode 22:05:58   AutoStart Delayed Session delayed due to cloud 22:06:01 Session Pending Session pending (2025-08-26) 22:06:03 Session Initiating Session initiating (2025-08-26) 22:06:23   Camera1 Connected SBIG Camera connected (Set point -10°C) 22:06:29   Plan Requested Observing Plan requested from AstroPlan (1.43.14) 22:07:02   Plan Loaded Observing Plan loaded to queue (Plan ID: 1138) 22:07:41   Telescope Connected Telescope connected (TheSky6) 22:08:06 Session Equilibration Session ready to Open Dome 22:08:51   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 22:09:31 Session Running Session running 22:09:34   Queue Started Observing Queue started (21 targets selected) 22:09:36     Target Started (NrZen) Target started (Focus Field 19, HIP 93376) 22:09:51       Dome Unparked Dome unparked 22:12:43       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:15:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide) 22:17:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 1) 22:17:05       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 22:18:49       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 22:20:27       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 22:20:46     Target Completed (NrZen) Target completed (Focus Field 19, HIP 93376) 22:22:57     Target Started (1/21) Target started (1/21, NGC 5957 w/SN2025fvw) 22:26:30       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:29:18       Focusing Completed Foc1 AutoFocus Completed (Profile No 3) 22:45:32     Target Completed Target completed (1/21, NGC 5957 w/SN2025fvw) 22:45:36     Target Started (2/21) Target started (2/21, UGC 10058 w/SN2025gvs) 22:51:01       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:53:38       Focusing Completed Foc1 AutoFocus Completed (Profile No 4) 23:09:56     Target Completed Target completed (2/21, UGC 10058 w/SN2025gvs) 23:10:00     Target Started (3/21) Target started (3/21, T CrB) 23:13:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:15:16       Focusing Completed Foc1 AutoFocus Completed (Profile No 5) 23:19:20     Target Completed Target completed (3/21, T CrB) 23:19:24     Target Started (4/21) Target started (4/21, UGC 10809 w/AT2025vaw) 23:22:45       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:24:50       Focusing Completed Foc1 AutoFocus Completed (Profile No 6) 23:40:46     Target Completed Target completed (4/21, UGC 10809 w/AT2025vaw) 23:40:51     Target Started (5/21) Target started (5/21, Nova Ser 2025) 23:44:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:46:54       Focusing Completed Foc1 AutoFocus Completed (Profile No 7) 23:52:51     Target Completed Target completed (5/21, Nova Ser 2025) 23:53:13     Target Started (6/21) Target started (6/21, SN 2025taz) 23:57:20       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:58:06       Focusing Failed Foc1 focusing failed - star lost 00:14:16     Target Completed Target completed (6/21, SN 2025taz) 00:15:33     Target Started (7/21) Target started (7/21, Nova Per 2020) 00:20:04       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:22:16       Focusing Completed Foc1 AutoFocus Completed (Profile No 9) 00:38:30     Target Completed Target completed (7/21, Nova Per 2020) 00:38:34     Target Started (8/21) Target started (8/21, UGC 1206 w/SN2025pao) 00:42:13       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:44:39       Focusing Completed Foc1 AutoFocus Completed (Profile No 10) 01:00:51     Target Completed Target completed (8/21, UGC 1206 w/SN2025pao) 01:00:55     Target Started (9/21) Target started (9/21, UGC 1814 w/SN2025oas) 01:04:05       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-LSI) 01:20:10     Target Completed Target completed (9/21, UGC 1814 w/SN2025oas) 01:22:13     Target Started (10/21) Target started (10/21, GSC 1224:29) 01:25:38       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-LSI) 01:32:12     Target Completed Target completed (10/21, GSC 1224:29) 01:34:41     Target Started (11/21) Target started (11/21, WDS GRB 34) 01:37:43       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:39:52       Focusing Completed Foc1 AutoFocus Completed (Profile No 11) 01:41:50     Target Completed Target completed (11/21, WDS GRB 34) 01:43:08     Target Started (12/21) Target started (12/21, GCVS HH And) 01:46:11       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:47:54       Focusing Failed Foc1 focusing failed (failed QC check - RmsE) 01:49:44     Target Completed Target completed (12/21, GCVS HH And) 01:51:25     Target Started (13/21) Target started (13/21, 61 Cyg) 01:53:43       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:55:48       Focusing Completed Foc1 AutoFocus Completed (Profile No 13) 01:57:41     Target Completed Target completed (13/21, 61 Cyg) 01:58:42     Target Started (14/21) Target started (14/21, NGC 7331 w/SN2025rbs) 02:22:11     Target Completed Target completed (14/21, NGC 7331 w/SN2025rbs) 02:22:15     Target Started (15/21) Target started (15/21, GCVS BL Lac) 02:25:20       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:27:46       Focusing Completed Foc1 AutoFocus Completed (Profile No 14) 02:31:32     Target Completed Target completed (15/21, GCVS BL Lac) 02:31:37     Target Started (16/21) Target started (16/21, GCVS Z And) 02:35:26       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:36:25   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 02:36:27   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 02:36:29       Focusing Aborted Foc1 Focusing Aborted 02:36:31     Target Aborted (16/21) Target aborted (16/21, GCVS Z And) due to cloud 02:36:33   Queue Paused Queue paused for Session Suspension 02:36:35 Session Suspending Session suspending 02:37:20   Dome Closed Dome closed (Closing time 49s, Zigbee 43s) 02:37:23 Session Suspended Session suspended 02:41:10     Target Cancelled Target cancelled (16/21, GCVS Z And) due to cloud 02:52:06 Session Resuming Session resuming 02:52:51   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 02:52:53 Session Running Session running 02:52:55   Queue Resumed Observing Queue resumed 02:52:58     Target Started (17/21) Target started (17/21, UGC 4973 w/SN2025ovr) 03:08:59     Target Completed Target partially completed (17/21, UGC 4973 w/SN2025ovr) 03:09:03     Target Started (18/21) Target started (18/21, NSV 14339) 03:10:22   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 03:10:24   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 03:10:26     Target Aborted (18/21) Target aborted (18/21, NSV 14339) due to cloud 03:10:28   Queue Paused Queue paused for Session Suspension 03:10:30 Session Suspending Session suspending 03:11:17   Dome Closed Dome closed (Closing time 49s, Zigbee 43s) 03:11:19 Session Suspended Session suspended 03:23:18 Session Resuming Session resuming 03:24:03   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 03:24:05 Session Running Session running 03:24:07   Queue Resumed Observing Queue resumed 03:24:10     Target Started (18/21) Target started (18/21, NSV 14339) 03:41:46     Target Completed Target completed (18/21, NSV 14339) 03:43:31     Target Started (19/21) Target started (19/21, GCVS RX And) 03:46:22       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:48:48       Focusing Completed Foc1 AutoFocus Completed (Profile No 16) 03:51:17     Target Completed Target completed (19/21, GCVS RX And) 03:52:52     Target Started (20/21) Target started (20/21, C/2020 T2 (Palomar)) 03:58:50       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 04:01:01       Focusing Completed Foc1 AutoFocus Completed (Profile No 17) 04:15:42     Target Completed Target completed (20/21, C/2020 T2 (Palomar)) 04:15:47     Target Started (21/21) Target started (21/21, Gliese 65) 04:27:41     Target Completed Target completed (21/21, Gliese 65) 04:27:43   Queue Completed Job Queue completed 04:27:47 Session Closing Session closing 04:28:42   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 04:29:31   Dome Parked Dome parked (parking time 42s), Az: 90.0 deg 04:30:06   Telescope Parked Telescope parked (parking time 27s total) 04:30:36   Telescope State Handbox reads 'Scope parked Turn scope off.' 04:30:58   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 04:32:24   Services Stopped Night Services stopped 04:32:27 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 04:33:09     Dome (Find Park) Find Park started (Search Az 88.0 to 92.0°, Step 0.2°, Narrow) 04:33:54     Dome Find Park found (Best Park Az 90.4°) 04:34:00     Dome Dome has been synced at park position (Az 90.0°, Adjustment: -0.4°) 04:34:02   Dome Parked Dome parked 04:34:17   Dome Charging Dome is parked and re-charging Ok (14mA) 04:34:19 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 04:34:17 Green Clear Dome Charging Dome is parked and re-charging Ok (14mA)

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Operational Issues (2025-08-26 S1352)

• Critical Issues (0)
• Major Issues (0)
• Minor Issues (0)
• Small Defects (2)
• Continuous Improvement (4)
• Figures (4)
  

Critical Issues

• None

Major Issues

• None

Minor Issues

• None

Small Defects

• One target had an anomously large slew error of around 0.75°  (01:58) . Whilst nearly all target had a slew error of < 5' one target (NGC 7331) had a slew error of 45.4' with the majority of error being in the RA direction (east/west). After centering the pointing error came down to 0.22' (after 2 centering movements). Closed after review 2025-08-27.
  Closed after review 2025-08-27 (Session, Telescope)
   
• Linking of VR frames for RX And was difficult frames contain high number of false star objects (post session VMA).  'Show Inventory' operations on 8s R and 10s frames for RX And (acquired at CCD Temp -10°C) contained a very high number of star objects (1700 to 3080) when using standard DETECT_THRESH of 8.0 - see 10s V image #1352247 (Fig 1) . Investigating showed that the problem did not present itself when carrying out the same operation on Raw Frame (see Fig 2). At first sight the 10s V image looks relatively normal (though the number of hot pixels lremaining looks higher than expected) See Fig 3a, but restricting the historgram range to just 98 to 108) reveals 'hot pixels's that lead to false star detections (see Fig 3b). The two filter sets (R and V) use different master dark frame / master flat frame pairs. Whilst the master frames look normal, the master dark frames for 8s and 10s are old ones (and the application of master darks with cold pixels could lead to a reduced image with 'pseudo hot pixels') In contrast the Master Flat frames (Jul 2025) are recent. In the event the Vma2 operation automatically changed the  DETECT_THRESH from 8.0  to 50.0 that lowered the star count from 2479 to 199 and allowed the image to link (plate solve) ok.   A separate continuous improvement ticket has been raised to collect a new set of master dark frames for -10°C which was completed 2025-09-01. The raw images from RX And were reduced using the new master darks on 2025-09-01, but the issue with high number of 'hot' pixels / leading to false stars in Star Inventory persisted. Issue can be fixed by changing 'Background filter size' from 1 to 3 in CCDSoft's Source Extraction Setup. The number of Inventory objects drops to just 29 (from the original number of 2479 !).  The effect of changing the parameter is however short lived and following a Detection Threshold change made by AstroMain the issue returns.  This happens because the 'default.sxt'  file "C:\Program Files (x86)\Software Bisque\CCDSoft Version 5\Configuration Files\DEFAULT.sxt" contains the original 'Background filter size' of 1. Finally fixed by changing 'BACK_FILTERSIZE 3.000000'  (Background filter size)  (from 2.000  in 'DEFAULT.sxt' file.  and by forcing the following row when setting DETECT_THRESHOLD via code. Also turned off ReadOnly flag on 'default.sex' file and changed BACK_FILTERSIZE 1 to BACK_FILTERSIZE 3
    S = "BACK_FILTERSIZE 3.000000 # Background filter: <size> or <width>,<height>"
  But still doesn't fix issue for 1 particular FIT file   "And_RX.20250827.im1352251.10s.V.FIT". Reclosed after review 2025-09-03 but continue to monitor.
  Closed after review 2025-09-03 (Session, SBIG Camera, VMA Analysis)