David's Astronomy Pages Notes - Session 1357 (2025-09-04)

Notes (S1356)

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Notes (S1358)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (0),  Minor Issues (1),  Small Defects (1),  Continuous Improvement (1)
	- Figures (4)
	Images from 2025-09-04  >>

Session Aims & Highlights (2025-09-04)

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. NGC 6802.  Carry out set of test exposures of open cluster NGC 6802, looking at magnitude reach with different exposures (10, 20, 60 & 120s).

 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 3.77.11,  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 3.24.6,  AstroObsCam 1.11.4 (not 1.11.5), AstroNorthCam 1.6.1, AstroLaunch 1.13.6

Highlights

• Targets. 17/22 planned targets were successfully completed, with 1 target partially completed . Other targets failed due cloud  / suspension session. One of planned targets (T CrB initially failed due to cloud, was acquired as a follow-up ToO target. In addition 1 ToO target (NGC 6802)) was partially (through suffficiently) completed.
• NGC 6802.  Image acquired for NGC 6802. Although cloud prevented all images, sufficient test exposure images were acquired for the purposes required.
• 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 21:58:30 Session Monitoring AutoStart monitoring for Live Session opportunity between 21:58 & 04:26 21:58:34 Session AutoStarting Session autostarting (21:58) 21:58:47   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 21:59:01 Session Created Session Created (Live, 2025-09-04 S01357, ImageSaveNum: 1357001) 21:59:08   Scope Switched On Telescope Power has been switched on via UPB Switch 22:00:53   Services Started Observatory Services started 22:01:03 Observatory (Auto) Observatory placed in Fully-Automated Mode 22:01:05 Session Pending Session pending (2025-09-04) 22:01:07 Session Initiating Session initiating (2025-09-04) 22:01:26   Camera1 Connected SBIG Camera connected (Set point -10°C) 22:01:33   Plan Requested Observing Plan requested from AstroPlan (1.43.14) 22:01:59   Plan Loaded Observing Plan loaded to queue (Plan ID: 1143) 22:02:40   Telescope Connected Telescope connected (TheSky6) 22:03:05 Session Equilibration Session ready to Open Dome 22:03:51   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 22:04:36 Session Running Session running 22:04:39   Queue Started Observing Queue started (22 targets selected) 22:04:42     Target Started (NrZen) Target started (Focus Field 20, HIP 99625) 22:04:55       Dome Unparked Dome unparked 22:07:11       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:10:29       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide) 22:12:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 1) 22:12:29       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 22:14:09       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 22:15:44       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 22:16:03     Target Completed (NrZen) Target completed (Focus Field 20, HIP 99625) 22:16:39     Target Aborted (1/22) Target aborted (1/22, AT2025usz) due to Priority 1 ToO Target 22:16:43     Target Started (2/23) Target started (2/23, NGC 6802, ToO) 22:19:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:22:12       Focusing Completed Foc1 AutoFocus Completed (Profile No 3) 22:37:06     Target Aborted (2/23) Target aborted (2/23, NGC 6802, ToO) due to User Intervention 22:38:26     Target Aborted (3/23) Target aborted (3/23, UGC 10809 w/SN2025vaw) due to Priority 1 ToO Target 22:38:30     Target Started (4/24) Target started (4/24, GCVS GK Per, ToO) 22:38:46   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 22:38:48   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 22:38:55     Target Aborted (4/24) Target aborted (4/24, GCVS GK Per, ToO) due to cloud 22:38:58   Queue Paused Queue paused for Session Suspension 22:39:00 Session Suspending Session suspending 22:39:46   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 22:39:49 Session Suspended Session suspended 22:48:27     Target Cancelled Target cancelled (4/24, GCVS GK Per, ToO) due to cloud 23:06:19 Session Resuming Session resuming 23:07:04   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 23:07:05 Session Running Session running 23:07:08   Queue Resumed Observing Queue resumed 23:07:10     Target Started (5/24) Target started (5/24, T CrB) 23:13:29       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 23:18:24     Target Completed Target partially completed (5/24, T CrB) 23:18:26   Queue Paused Queue paused for Session Suspension 23:18:28 Session Suspending Session suspending 23:19:15   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 23:19:17 Session Suspended Session suspended 23:24:53     Target Cancelled Target cancelled (6/24, Nova Ser 2025) due to cloud 23:36:01 Session Resuming Session resuming 23:36:46   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 23:36:48 Session Running Session running 23:36:50   Queue Resumed Observing Queue resumed 23:36:53     Target Started (7/24) Target started (7/24, AT2023yga) 23:50:16     Target Completed Target partially completed (7/24, AT2023yga) 23:50:20     Target Started (8/24) Target started (8/24, C/2024 E1 (Wierzchos)) 23:53:02       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:55:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 4) 00:03:37     Target Completed Target completed (8/24, C/2024 E1 (Wierzchos)) 00:03:41     Target Started (9/25) Target started (9/25, T CrB, ToO) 00:06:56       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:09:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 5) 00:13:07     Target Completed Target completed (9/25, T CrB, ToO) 00:13:09     Target Missed (10/25) Target's time slot was missed (10/25, GCVS BL Lac) 00:13:11     Target Started (11/25) Target started (11/25, AT2022vyq (CV)) 00:16:42       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:18:49       Focusing Completed Foc1 AutoFocus Completed (Profile No 6) 00:25:02     Target Completed Target completed (11/25, AT2022vyq (CV)) 00:25:06     Target Started (12/25) Target started (12/25, AT2025wbs) 00:28:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:30:55       Focusing Completed Foc1 AutoFocus Completed (Profile No 7) 00:46:51     Target Completed Target completed (12/25, AT2025wbs) 00:47:27     Target Started (13/25) Target started (13/25, GCVS CY Lyr) 00:50:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:52:28       Focusing Completed Foc1 AutoFocus Completed (Profile No 8) 00:56:12     Target Completed Target completed (13/25, GCVS CY Lyr) 00:57:45     Target Started (14/25) Target started (14/25, C/2017 K2 (PANSTARRS)) 01:03:34       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:06:04       Focusing Completed Foc1 AutoFocus Completed (Profile No 9) 01:17:47     Target Completed Target completed (14/25, C/2017 K2 (PANSTARRS)) 01:17:52     Target Started (15/25) Target started (15/25, SN 2025taz) 01:21:54       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:24:02       Focusing Completed Foc1 AutoFocus Completed (Profile No 10) 01:40:00     Target Completed Target completed (15/25, SN 2025taz) 01:40:05     Target Started (16/25) Target started (16/25, AT2025md (CV)) 01:43:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:45:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 11) 01:51:20     Target Completed Target completed (16/25, AT2025md (CV)) 01:51:24     Target Started (17/25) Target started (17/25, MilkyWay w/AT2025rud) 01:55:04       Focusing Skipped Foc1 focusing skipped - unable to find a star (TCF-LSI) 02:11:21     Target Completed Target completed (17/25, MilkyWay w/AT2025rud) 02:11:45     Target Started (18/25) Target started (18/25, UGCA 23) 02:16:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:18:29       Focusing Completed Foc1 AutoFocus Completed (Profile No 12) 02:34:41     Target Completed Target completed (18/25, UGCA 23) 02:34:45     Target Started (19/25) Target started (19/25, AT2023ct (CV)) 02:37:46       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:40:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 13) 02:46:04     Target Completed Target completed (19/25, AT2023ct (CV)) 02:46:25     Target Started (20/25) Target started (20/25, AT2025voc) 02:50:05       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:52:32       Focusing Completed Foc1 AutoFocus Completed (Profile No 14) 03:08:27     Target Completed Target completed (20/25, AT2025voc) 03:08:31     Target Started (21/25) Target started (21/25, AT2022arp (CV)) 03:11:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:13:16       Focusing Completed Foc1 AutoFocus Completed (Profile No 15) 03:19:28     Target Completed Target completed (21/25, AT2022arp (CV)) 03:20:45     Target Started (22/25) Target started (22/25, GCVS RX And) 03:24:07       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:26:11       Focusing Completed Foc1 AutoFocus Completed (Profile No 16) 03:29:14     Target Completed Target completed (22/25, GCVS RX And) 03:30:05     Target Started (23/25) Target started (23/25, AT2025lc (CV)) 03:33:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:35:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 17) 03:41:52     Target Completed Target completed (23/25, AT2025lc (CV)) 03:42:25     Target Started (24/25) Target started (24/25, C/2025 A6 (Lemmon)) 03:47:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:49:49       Focusing Completed Foc1 AutoFocus Completed (Profile No 18) 04:07:12     Target Completed Target completed (24/25, C/2025 A6 (Lemmon)) 04:07:16     Target Started (25/25) Target started (25/25, SN 2025jtq) 04:30:08     Target Completed Target completed (25/25, SN 2025jtq) 04:30:10   Queue Completed Job Queue completed 04:30:13 Session Closing Session closing 04:31:06   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 04:32:04   Dome Parked Dome parked (parking time 50s), Az: 90.0 deg 04:32:38   Telescope Parked Telescope parked (parking time 30s total) 04:33:02   Telescope State Handbox reads 'Scope parked Turn scope off.' 04:34:05   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 04:35:28   Services Stopped Night Services stopped 04:35:31 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 04:35:58     Dome (Find Park) Find Park started (Search Az 80.0 to 100.0°, Step 1.0°, Wide) 04:36:42     Dome Find Park found (Best Park Az 88.0°) 04:36:48     Dome (Find Park) Find Park started (Search Az 86.0 to 90.0°, Step 0.2°, Narrow) 04:37:32     Dome Find Park found (Best Park Az 87.8°) 04:37:38     Dome Dome has been synced at park position (Az 90.0°, Adjustment: +2.2°) 04:37:40   Dome Parked Dome parked 04:38:11   Dome Charging Dome is parked and re-charging Ok (59mA) 04:38:13 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 04:38:11 Green Clear Dome Charging Dome is parked and re-charging Ok (59mA)

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Operational Issues (2025-09-04 S1357)

• Critical Issues (0)
• Major Issues (0)
• Minor Issues (1)
• Small Defects (1)
• Continuous Improvement (1)
• Figures (4)
  

Critical Issues

• None

Major Issues

• None

Minor Issues

• There was a major shift of in magnetometer readings at  (2025-09-04 11:35 UT).  The X axis magnetometer readings took a major +5000nT shift in readings at around 11:35 UT (12:35 LT). At the same time there was a smaller negative shift in Z axis readings (See Fig 1). At the time the Y axis sensor and the Temperature Sensor were disabled for diagnostic runs looking into the potential causes of other earlier shifts is magnetometer readings though none of these was as dramatic a shift as this new example.  Reading remained analomalous for over 24 hours. A detailed chart looking at raw uncorrected values show the anomaly starting at 11:35 - 11:36 UT (see Fig 2).  At this time the UPS Monitor issued a red alert with message "Mains Power Outage/Glitch at 12:35:59 LT, which is 11:35:59 UT and within the time window of the start of the magnetometer anomaly (see Fig 3).  It is unclear whether a) a minor outage or voltage fluctuation in the Mains Supply caused the UPS system to switch to Battery Supply but in such a way that upset the SAM Unit and led to the issue with the magnetometer readings, or whether b) an EMI or voltage change in the SAM Magnetometers/SAM Unit (seen as the 5000 nT magnetometer shift in X axis readings) somehow fed back to UPS system and caused it to switch from Mains to Battery Supply.  This is the first time that should a correlation has occurred.  Previous shifts/spikes in magnetometer readings have happened on multiple occasions before without there bing any associated UPS Alert.  The data demonstrating the correlation between the Magnetometers Anomaly and UPS Supply Change was reviewed 2025-09-06. Now need to consider the implications of this, and what mitigating action could be taken ?
  To review and consider further 2025-09-05+ (UPS System,  Power Supply, Magnetometer Station) 

Small Defects

• UPS Monitor issued an alert with message "Mains Power Outage/Glitch" (2025-09-04 12:35).  The UPS Monitor issued a red alert with message "Mains Power Outage/Glitch at 12:35:59 (which is 11:35:59 UT).  No apparent issues/problems were noted or logged . A green all-clear was issued 5-6s later at 12:36:05 with the message "UPS running on Mains Power at 12:36:04 (outage time 5.0s)". (See Fig 3). The Magnetometer X readings began to play up at around this time. Investigating further showed a near perfect correlation between the time of the UPS Alert (11:35:59 UT) and the time that that the magnetometer anomaly started (11:35 / 11:36 UT). Closed after review 2025-09-06. Further review/consideration will be conducted as part of the Magnetometer Anomaly Issue (above)
  Closed 2025-09-06 (UPS System,  Power Supply, Magnetometer Station)