David's Astronomy Pages Notes - Session 1416 (2026-04-03)

Notes (S1415)

Notes Main

Home Page

Notes (S1417)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (0),  Minor Issues (3),  Small Defects (2),  Continuous Improvement (1)
	- Figures (1)
	Images from 2026-04-03  >>

Session Aims & Highlights (2026-04-03)

Main aims

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

 Equipment & Software

• 12" LX200 and ST-10XME
• 80mm APO and ZWO ASI 178MC
• TheSky6 6.0.0.65, CCDSoft 5.00.201 (Reinstall), DeviceHub 7.1.0.4707, MeadeGeneric 1.3.12.522, UPB 3,  Pulsar Dome Firmware 1.51 & Driver 6.3.10
• Pegasus-UI 2.10, Peg-Focuser 2.10, Peg-Switch 2.10, TCF-LSI 3.3.5
• SharpCap 3.2, PHD2  2.6.13, Siril 1.4.1, deCONZ 1.18.2, ASCOM 7.1.0.4707
   
• AstroMain 3.81.4  AstroPlan 1.46.2, AstroShCap 1.3.23, AstroGuard 1.13.2  (any new items or versions in bold)
  AstroMag 1.5.12, AstroVOE 1.16,  AstroSN 1.16,  AstroProtect 1.10.6,  AstroMove 1.18.1
  AstroAllSky 3.27.7, AstroWeather 1.30.2,   AstroObsCam 1.13.1, AstroNorthCam 1.8.1, AstroLaunch 1.14.9

Highlights

• Targets. 14/25 planned targets were completed with 6 targets partially completed from the two plans executed (V1 and V2). Several targets were only partically completely due to false rain alerts (associated with unstable rain sensor calibrations).  Other targets were missed due to displacement by two ShCap targets (M92 & NGC 4216) that were injected into the Job Queue as ToO's.
•  Dome. No issues open/closing shutter. Dome was successfully parked at the end of the session.

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 21:04:40 Session Monitoring AutoStart monitoring for Live Session opportunity between 21:04 & 04:38 21:04:43 Session AutoStarting Session autostarting (21:04) 21:04:49 Session Created Session Created (Live, 2026-04-03 S01416) 21:04:52   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 21:05:11   Scope Switched On Telescope Power has been switched on via UPB Switch 21:07:01   Services Started Observatory Services started 21:07:10 Observatory (Auto) Observatory placed in Fully-Automated Mode 21:07:13 Session Pending Session pending (2026-04-03) 21:07:15 Session Initiating Session initiating (2026-04-03) 21:07:39   Camera1 Connected SBIG Camera connected (Set point -20°C) 21:07:45   Plan Requested Observing Plan requested from AstroPlan (1.46.2) 21:10:01   Plan Loaded Observing Plan loaded to queue (PlanID: 1215) 21:10:42   Telescope Connected Telescope connected (TheSky6) 21:11:06 Session Equilibration Session ready to Open Dome 21:11:51   Dome Opened Dome opened (Opening time 45s, Zigbee 41s) 21:11:54 Session Running Session running 21:11:56   Queue Started Observing Queue started (14 targets selected) 21:12:01     Target Started (NrZen) Target started (Focus Field 10, HIP 49253) 21:12:16       Dome Unparked Dome unparked 21:16:52       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 21:18:37   Critical Rain Alert Critical Rain Alert (Obs.Manager will close the Dome) 21:18:39   HardSuspend Called Hard Suspend called due to Critical Conditions (rain) 21:18:41       Focusing Aborted Foc1 Focusing Aborted due to HardSuspend 21:18:43     Target Aborted (NrZen) Target aborted (Focus Field 10, HIP 49253) due to rain 21:18:45   Queue Paused Observing Queue pausing for Session Suspension 21:18:47 Session Suspending Session suspending 21:19:32   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 21:19:34 Session Suspended Session suspended 21:21:48 Session Resuming Session resuming 21:22:33   Dome Opened Dome opened (Opening time 45s, Zigbee 41s) 21:22:35 Session Running Session running 21:22:37   Queue Resumed Observing Queue resumed 21:22:39     Target Started (1/14) Target started (1/14, UGC 5607 w/SN2026kc) 21:25:21       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 21:27:28       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 21:29:19       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 21:31:23       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-LSI) 21:47:31     Target Completed Target completed (1/14, UGC 5607 w/SN2026kc) 21:47:35     Target Started (2/14) Target started (2/14, NGC 4206) 21:51:56       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 21:55:55       Focusing Completed Foc1 AutoFocus Completed (Profile No 3, wide) 21:57:21   Critical Rain Alert Critical Rain Alert (Obs.Manager will close the Dome) 21:57:23   HardSuspend Called Hard Suspend called due to Critical Conditions (rain) 21:57:25       Focusing Aborted Foc1 Focusing Aborted 21:57:27     Target Aborted (2/14) Target aborted (2/14, NGC 4206) due to rain 21:57:29   Queue Paused Queue paused for Session Suspension 21:57:31 Session Suspending Session suspending 21:58:16   Dome Closed Dome closed (Closing time 49s, Zigbee 44s) 21:58:18 Session Suspended Session suspended 22:00:21 Session Resuming Session resuming 22:01:06   Dome Opened Dome opened (Opening time 45s, Zigbee 41s) 22:01:08 Session Running Session running 22:01:10   Queue Resumed Observing Queue resumed 22:01:13     Target Started (2/14) Target started (2/14, NGC 4206) 22:12:59     Target Completed Target partially completed (2/14, NGC 4206) 22:13:03     Target Started (3/14) Target started (3/14, UGC 9533 w/AT2026hvo) 22:34:00     Target Completed Target completed (3/14, UGC 9533 w/AT2026hvo) 22:34:04     Target Started (4/14) Target started (4/14, NGC 3689 w/SN2026gwx) 22:54:05     Target Completed Target completed (4/14, NGC 3689 w/SN2026gwx) 22:54:09     Target Started (5/14) Target started (5/14, NGC 4205 w/SN2026fvx) 22:54:51   Critical Rain Alert Critical Rain Alert (Obs.Manager will close the Dome) 22:54:53   HardSuspend Called Hard Suspend called due to Critical Conditions (rain) 22:54:57     Target Aborted (5/14) Target aborted (5/14, NGC 4205 w/SN2026fvx) due to rain 22:54:59   Queue Paused Queue paused for Session Suspension 22:55:01 Session Suspending Session suspending 22:55:51   Dome Closed Dome closed (Closing time 50s, Zigbee 44s) 22:55:53 Session Suspended Session suspended 23:03:47 Session Resuming Session resuming 23:04:32   Dome Opened Dome opened (Opening time 45s, Zigbee 41s) 23:04:35 Session Running Session running 23:04:37   Queue Resumed Observing Queue resumed 23:04:39     Target Started (5/14) Target started (5/14, NGC 4205 w/SN2026fvx) 23:17:48     Target Completed Target partially completed (5/14, NGC 4205 w/SN2026fvx) 23:17:52     Target Started (6/14) Target started (6/14, 29P/Schwassmann-Wachmann) 23:22:29       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:25:49       Focusing Completed Foc1 AutoFocus Completed (Profile No 4, wide) 23:28:19       Focusing Completed Foc1 AutoFocus Completed (Profile No 4) 23:38:28     Target Completed Target partially completed (6/14, 29P/Schwassmann-Wachmann) 23:38:32     Target Started (7/14) Target started (7/14, NGC 3660 w/SN2026cff) 23:51:31   Critical Rain Alert Critical Rain Alert (Obs.Manager will close the Dome) 23:51:33   HardSuspend Called Hard Suspend called due to Critical Conditions (rain) 23:51:36     Target Aborted (7/14) Target aborted (7/14, NGC 3660 w/SN2026cff) due to rain 23:51:38   Queue Paused Queue paused for Session Suspension 23:51:40 Session Suspending Session suspending 23:52:27   Dome Closed Dome closed (Closing time 50s, Zigbee 44s) 23:52:29 Session Suspended Session suspended 23:54:32 Session Resuming Session resuming 23:55:17   Dome Opened Dome opened (Opening time 45s, Zigbee 41s) 23:55:19 Session Running Session running 23:55:21   Queue Resumed Observing Queue resumed 23:55:24     Target Started (8/15) Target started (8/15, M92, ToO). Using SharpCap 23:58:11       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:00:20       Focusing Completed Foc1 AutoFocus Completed (Profile No 5) 00:26:50       Camera1 Connected SBIG Camera connected (Set point -25°C) 00:26:52     Target Completed Target completed (8/15, M92, ToO) 00:26:54     Target Missed (9/15) Target's time slot was missed (9/15, IC 700 w/SN2025aico) 00:26:57     Target Started (10/15) Target started (10/15, NGC 4914 w/SN2026fjc) 00:45:11     Target Completed Target partially completed (10/15, NGC 4914 w/SN2026fjc) 00:45:16     Target Started (11/16) Target started (11/16, NGC 4216, ToO). Using SharpCap 00:49:11       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI) 01:53:09       Camera1 Connected SBIG Camera connected (Set point -25°C) 01:53:11     Target Completed Target completed (11/16, NGC 4216, ToO) 01:53:13     Target Missed (12/16) Target's time slot was missed (12/16, IC 4556 w/SN2026fuz) 01:53:15     Target Missed (13/16) Target's time slot was missed (13/16, T CrB) 01:53:17     Target Missed (14/16) Target's time slot was missed (14/16, GCVS CY Lyr) 01:53:19     Target Missed (15/16) Target's time slot was missed (15/16, GCVS AM Her) 01:53:21     Target Started (16/16) Target started (16/16, AT2026cqc (CV)) 02:01:48     Target Completed Target partially completed (16/16, AT2026cqc (CV)) 02:01:50   Queue Completed Job Queue completed 02:01:52 Session Continuing Session continuing 02:02:02   Plan Requested Observing Plan requested from AstroPlan (1.46.2) 02:02:38   Plan Loaded Observing Plan loaded to queue (PlanID: 1216) 02:02:40 Session Running Session running 02:02:42   Queue Started Observing Queue started (11 targets selected) 02:02:53     Target Started (1/11) Target started (1/11, IC 4556 w/SN2026fuz) 02:06:36       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:08:53       Focusing Completed Foc1 AutoFocus Completed (Profile No 6) 02:25:10     Target Completed Target completed (1/11, IC 4556 w/SN2026fuz) 02:25:14     Target Started (2/11) Target started (2/11, T CrB) 02:28:29       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:30:44       Focusing Completed Foc1 AutoFocus Completed (Profile No 7) 02:34:52     Target Completed Target completed (2/11, T CrB) 02:34:56     Target Started (3/11) Target started (3/11, GCVS AM Her) 02:38:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:40:54       Focusing Completed Foc1 AutoFocus Completed (Profile No 8) 02:45:46     Target Completed Target completed (3/11, GCVS AM Her) 02:46:03     Target Started (4/11) Target started (4/11, GCVS CY Lyr) 02:49:33       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:51:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 9) 02:55:52     Target Completed Target completed (4/11, GCVS CY Lyr) 02:56:21     Target Started (5/11) Target started (5/11, LEDA 68428 w/SN2025acqv) 03:00:39       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:03:15       Focusing Completed Foc1 AutoFocus Completed (Profile No 10) 03:19:15     Target Completed Target completed (5/11, LEDA 68428 w/SN2025acqv) 03:19:19     Target Started (6/11) Target started (6/11, M31 w/M31N 2026-02a) 03:23:05       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI) 03:39:12     Target Completed Target completed (6/11, M31 w/M31N 2026-02a) 03:40:22     Target Started (7/11) Target started (7/11, GCVS BL Lac) 03:43:45       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:46:08       Focusing Completed Foc1 AutoFocus Completed (Profile No 11) 03:49:56     Target Completed Target completed (7/11, GCVS BL Lac) 03:50:39     Target Started (8/11) Target started (8/11, AT2026hur) 03:55:01       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 03:57:11       Focusing Completed Foc1 AutoFocus Completed (Profile No 12) 04:13:28     Target Completed Target completed (8/11, AT2026hur) 04:13:32     Target Started (9/11) Target started (9/11, 10P/Tempel) 04:17:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 04:19:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 13) 04:29:27     Target Completed Target completed (9/11, 10P/Tempel) 04:29:31     Target Started (10/11) Target started (10/11, C/2023 R1 (PANSTARRS)) 04:33:44       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 04:36:21       Focusing Completed Foc1 AutoFocus Completed (Profile No 14) 04:44:55     Target Completed Target completed (10/11, C/2023 R1 (PANSTARRS)) 04:44:59     Target Started (11/11) Target started (11/11, C/2025 R3 (PANSTARRS)) 04:48:59       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 04:51:25       Focusing Completed Foc1 AutoFocus Completed (Profile No 15) 05:01:08     Target Completed Target completed (11/11, C/2025 R3 (PANSTARRS)) 05:01:10   Queue Completed Job Queue completed 05:01:11 Session Closing Session closing 05:02:01   Dome Closed Dome closed (Closing time 49s, Zigbee 44s) 05:02:19   Dome Parked Dome parked (parking time 10s), Az: 90.0 deg 05:03:12   Telescope Parked Telescope parked (parking time 48s total) 05:03:36   Telescope State Handbox reads 'Scope parked Turn scope off.' 05:04:33   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 05:05:58   Services Stopped Night Services stopped 05:06:01 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 05:06:39     Dome (Find Park) Find Park started (Search Az 88.0 to 92.0°, Step 0.2°, Narrow) 05:07:23     Dome Find Park found (Best Park Az 90.7°) 05:07:28     Dome Dome has been synced at park position (Az 90.0°, Adjustment: -0.7°) 05:07:30   Dome Parked Dome parked 05:10:32   Dome Charging Dome hasn't started re-charging after 3.1 minutes 05:10:34 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 05:10:32 Red Alert Dome Charging Dome hasn't started re-charging after 3.1 minutes

Back to Top

Operational Issues (2026-04-03 S1416)

• Critical Issues (0)
• Major Issues (0)
• Minor Issues (3)
• Small Defects (2)
• Continuous Improvement (1)
• Figures (1)
  

[ Prev | Next ]

Critical Issues

• None

Major Issues

• None

Minor Issues

• AstroPlan's Schedule Builder wasn't able to make an observing plan that filled the entire night (21:07). AstroPlan was only able to make a plan lasting from 21:29 (Alt -12) to 01:52 (SunAlt -20+).  Although lots of PCG and Shakabazian targets were recently added to the Target's Database, these require dark skies (C1, C2) and not the bright (moonlit) skies (C3) during this particular session.  Several regular targets have been recently acquired and were not due.  Winds coming from the West direction meant that targets on the west side of the observatory were rejected during the schedule building reducing the number of available targets for the plan.  Need to have a wider ange of targets than can be acquired during brighter C3 conditons.  The option to 'Continue with new plan' was already selected in AstroMain, and the session continued ok.
  Closed 2026-04-05 (Session, Targets Database, User Awareness)
   
• Slew Table shows 3 slews to NGC 4205 (22:54 - 23:05). The slew table shows 3 slews to NGC 4205 made at 22:54, 23:04 and 23:05 (see table below).
  Slewing Details    Dome Slew               Telescope Slew                Overall
  Target    Time    Az1  Az2  Slew Angle   Az1  Az2   Alt1 Alt2  Slew Angle Slew
            hh:mm   deg  deg  time deg     deg  deg   deg  deg   time deg   time
  NGC 4205  22:54  158.0 80.9 35s  77.1   157.5 55.1  56.7 76.5  27s  49.1  36s
  NGC 4205  23:04   58.9 57.9  3s   1.0    53.8 53.8  77.6 77.6  12s   0.0  14s
  NGC 4205  23:05   57.9 57.9  0s   0.0    53.8 53.7  77.6 77.7  11s   0.0  13s
  Investigations show that the first slew was nearly complete when there was a critical rain alert (a false alert as it turned out), that led to the Slew being aborted, however the telescope had by then essentially reached the target and was settling.  Because the slew operation wasn't completed, the target was marked as having not made the slew. When the session resumed shortly after,  there was a further slew to the target. The telescope made a mininal slew (basicially a resettling of the scope) that rounded to effectively a 0.0 slew angle. Whilst the dome made a 1 deg Azimuthal slew , associated with the extra sidereal movement in target since the original slew. Working with current design the 0.0 selw angle from the telescope was interpreted by the Slew routine to have failed, and a 'second' slew attempt (now the third slew) was made.  Again there was minimal movement into the telescope and no movement from the dome. So the reasons for the 3 slews cab be explained.   The only gap in current design is that the routine that considers whether a '1st' telescope slew had failed, should consider the current distance of the telescope from the target before deciding that a 2nd slew should be made.
  Closed after review 2026-04-04 (Session, AstroMain, User Awareness)
   
• Rain Sensor values were unstable and led to a number of false Critical Rain Alerts during session (21:18, 21:57, 22:55.  23:51). The rain sensor values associated with the Observatory's Eurotech CloudSensor have been unstable for a while now, and would ideally be replaced except that Eurotech is not building new Sensors at moment due to component supply issues (http://www.auroraeurotech.com/CloudSensor.php).  When conditions are dry (as they were during the session),  the rain sensor would normally steadily fall and a trim setting can be used to 'normalise' the calibration to a working dry value.  However the values would occasionally increase and trip the trimmed 'wet' threshold and cause a hard suspend / session suspension. This happened a number of times during the session, and led to some targets being only partially completed. The task of resetting the 'rain trim' is lot easiest now, as it only needs to be made in AstroMain, and it cascades to AstroGuard, AstroWeather and AstroAllSky.  As an interim measure a Zigbee rain sensor product has been found online, and one has been ordered, but delivery will not be until early May. Until then manual adjustment of the rain trim needs to be made.
  Closed after review 2026-04-04 (Session, AstroMain, Eurotech CloudSensor, User Awareness)

Small Defects

• AstroWeather is incorrectly flagging CloudSensor data as being one hour old. AstroWeather is showing a red flag againgst CloudSensor data with message that data is one-hour old. CloudSensor timestamps are UTC times, and if incorrect datespan calculation is performed they can appear to be 1 hour old (eg looking at 21:15 UT when local time is 22:15 (22:15 - 21:15 = 01:00)   This is a bug and has appeared following the change in DST but introduced by the move to a common 'Date/Age' module, in Jan 2026. . Fixed in AstroWeather 1.30.3, the FormatDataAge() routine was previously allow the subtaction of a universal time from local time now(), the routine is modified to force the passed time value into utc and perform data age calculation in utc space.
  Fixed 2026-04-05 (AstroWeather 1.30.3)
   
• PageBuilder's 'Insert Mag' facility is allowing incorrect number value >1000 to enter the Photometric database .Whilst adding facility to list photometric results by VarStar it was noticed that the odd record would contain a measured magnitude of 1370.00.  This has evidentally occurred because the intended magnitude measurement of 13.78 was accidentally entered as 13,78 (with a comma) which was converted to 1378 on entry in database. Fixed in AstroMain 3.81.5,  commas are replaced by decimal place. Bad values fixed in Photometry database use btnFixBadResults_Click() routine in AstroVma.
  Fixed 2026-04-05 (AstroMain 3.81.5, AstroVMA 0.2.2, Photometry.DB)

Continuous Improvement

• Add target offset for Comet C/2025 R3 to get more of its tail in view. Comet C/2025 R3 (PANSTARRS) is currently being acquired with a normal  0 W, 0 N target offset.  This results in images that have the comet in the centre of the field of view.  Since the comet is sporting a tail, this is a suboptimal as part of the tail are cut off by the edge of the image.   It is proposed to get more of the tail in view, but adding offsets W 2.5' and N 1.5'. Implemented in Targets Database using AstroPlan Target Form ready for next session.
  Done 2026-04-04 (Targets Database)

[ Prev | Next ]

Back to Top Issue,  Back to Top

[ Prev | Next ]

Back to Top Issue,  Back to Top