David's Astronomy Pages Notes - Session 1441 (2026-07-26)

Notes (S1440)

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Notes (S1442)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (0),  Minor Issues (2),  Small Defects (2),  Continuous Improvement (1)
	- Figures (3)
	Images from 2026-07-26  >>

Session Aims & Highlights (2026-07-26)

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, CCDSoft5 5.0.201, DeviceHub 7.1.0.4707, MeadeGeneric 1.3.12.522, UPB 3, PulsarDome 6.4.0.0
• Peg-Unity 2.12, Peg-Focuser 2.12, Peg-Switch 2.12, TCF-LSI 3.3.5
• SharpCap 3.2.6482, PHD2 2.6.14, Siril 1.4.2, deCONZ 2.18.2, ASCOM 7.1.0.4707
   
• AstroMain 3.83.1, AstroPlan 1.47, AstroShCap 1.3.23, AstroGuard 1.13.2
  AstroMag 1.5.12, AstroVOE 2.0.1, AstroSN 1.16, AstroProtect 1.7, AstroMove 1.18.2
  AstroAllSky 3.28.1, AstroWeather 1.30.3, AstroObsCam 1.14, AstroNorthCam 1.10.2, AstroLaunch 1.14.9

Highlights

• Targets. 11/13 planned targets were completed with 1 target partially completely. The first target (T CrB)  initially failed due to cloud but was acquired as a ToO Target
•  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 22:05:44 Session Monitoring AutoStart monitoring for Live Session opportunity between 22:38 & 02:51 22:05:44   AutoStart Waiting AutoStart waiting till earliest start time at 22:38 22:38:27 Session AutoStarting Session autostarting (22:38) 22:38:33 Session Created Session Created (Live, 2026-07-26 S01441) 22:38:35   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 22:38:56   Scope Switched On Telescope Power has been switched on via UPB Switch 22:40:41   Services Started Observatory Services started 22:40:52 Observatory (Auto) Observatory placed in Fully-Automated Mode 22:40:54 Session Pending Session pending (2026-07-26) 22:40:56 Session Initiating Session initiating (2026-07-26) 22:41:16   Camera1 Connected SBIG Camera connected (Set point -10°C) 22:41:19   Plan Requested Observing Plan requested from AstroPlan (1.47) 22:42:54   Plan Loaded Observing Plan loaded to queue (PlanID: 1242) 22:43:36   Telescope Connected Telescope connected (TheSky6) 22:44:00 Session Equilibration Session ready to Open Dome 22:44:46   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 22:44:52   Equilibration Started Dome Equilibration started 22:44:54   Equilibration Ended Dome Equilibration ended (0.0 mins total) 22:44:56 Session Running Session running 22:44:58   Queue Started Observing Queue started (13 targets selected) 22:45:01     Target Started (NrZen) Target started (Focus Field 18, HIP 88232) 22:45:15       Dome Unparked Dome unparked 22:50:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:52:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide) 22:55:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 1) 22:55:12       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 22:57:01       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 22:58:47       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 22:59:09     Target Completed (NrZen) Target completed (Focus Field 18, HIP 88232) 23:19:12     Target Started (1/13) Target started (1/13, T CrB) 23:21:23   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 23:21:25   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 23:21:27     Target Aborted (1/13) Target aborted (1/13, T CrB) due to cloud 23:21:29   Queue Paused Queue paused for Session Suspension 23:21:31 Session Suspending Session suspending 23:22:14   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 23:22:19 Session Suspended Session suspended 23:29:33     Target Cancelled Target cancelled (1/13, T CrB) due to cloud 23:35:21 Session Resuming Session resuming 23:36:06   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 23:36:08 Session Running Session running 23:36:11   Queue Resumed Observing Queue resumed 23:36:13     Target Started (2/13) Target started (2/13, NGC 5907 w/SN2026kid) 23:40:12       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI) 23:56:23     Target Completed Target completed (2/13, NGC 5907 w/SN2026kid) 23:56:27     Target Started (3/14) Target started (3/14, T CrB, ToO) 00:00:16       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:02:34       Focusing Completed Foc1 AutoFocus Completed (Profile No 3) 00:06:44     Target Completed Target completed (3/14, T CrB, ToO) 00:06:48     Target Started (4/14) Target started (4/14, UGC 11058 w/SN2026ewd) 00:16:50     Target Completed Target partially completed (4/14, UGC 11058 w/SN2026ewd) 00:16:54     Target Started (5/14) Target started (5/14, AT2023acib) 00:20:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:22:47       Focusing Completed Foc1 AutoFocus Completed (Profile No 4) 00:31:40     Target Completed Target completed (5/14, AT2023acib) 00:31:44     Target Started (6/14) Target started (6/14, GCVS CI Cyg) 00:35:50       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:38:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 5) 00:41:18     Target Completed Target completed (6/14, GCVS CI Cyg) 00:41:22     Target Started (7/14) Target started (7/14, GCVS AM Her) 00:45:47       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:48:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 6) 00:53:01     Target Completed Target completed (7/14, GCVS AM Her) 00:53:05     Target Started (8/14) Target started (8/14, GCVS CY Lyr) 00:56:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:57:20       Focusing Failed Foc1 focusing failed - star lost 01:01:04     Target Completed Target completed (8/14, GCVS CY Lyr) 01:02:23     Target Started (9/14) Target started (9/14, AT2026lcz) 01:05:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:08:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 8) 01:24:28     Target Completed Target completed (9/14, AT2026lcz) 01:24:43     Target Started (10/14) Target started (10/14, NGC 6934) 01:28:34       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:30:52       Focusing Completed Foc1 AutoFocus Completed (Profile No 9) 01:49:03     Target Completed Target completed (10/14, NGC 6934) 01:49:08     Target Started (11/14) Target started (11/14, GCVS BL Lac) 01:52:28       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 01:54:48       Focusing Completed Foc1 AutoFocus Completed (Profile No 10) 01:58:38     Target Completed Target completed (11/14, GCVS BL Lac) 01:59:11     Target Started (12/14) Target started (12/14, IC 5191 w/SN2026myp) 02:02:30       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:05:01       Focusing Completed Foc1 AutoFocus Completed (Profile No 11) 02:21:36     Target Completed Target completed (12/14, IC 5191 w/SN2026myp) 02:21:40     Target Started (13/14) Target started (13/14, AT2026lck) 02:25:12       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI) 02:41:14     Target Completed Target completed (13/14, AT2026lck) 02:43:51     Target Started (14/14) Target started (14/14, 61 Cyg) 02:45:58       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 02:48:02       Focusing Completed Foc1 AutoFocus Completed (Profile No 12) 02:49:59     Target Completed Target completed (14/14, 61 Cyg) 02:50:01   Queue Completed Job Queue completed 02:50:04 Session Closing Session closing 02:50:54   Dome Closed Dome closed (Closing time 49s, Zigbee 43s) 02:52:01   Dome Parked Dome parked (parking time 55s), Az: 90.0 deg 02:52:55   Telescope Parked Telescope parked (parking time 44s total) 02:53:19   Telescope State Handbox reads 'Scope parked Turn scope off.' 02:53:57   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 02:55:21   Services Stopped Night Services stopped 02:55:24 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 02:55:56     Dome (Find Park) Find Park started (Search Az 88.0 to 92.0°, Step 0.2°, Narrow) 02:56:40     Dome Find Park found (Best Park Az 89.9°) 02:56:46     Dome Dome has been synced at park position (Az 90.0°, Adjustment: +0.1°) 02:56:48   Dome Parked Dome parked 02:59:50   Dome Charging Dome is parked and well charged (96%, 14.9v) 02:59:52 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 02:59:50 Yellow Alert Dome Charging Dome is parked and well charged (96%, 14.9v)

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Operational Issues (2026-07-26 S1441)

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

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Critical Issues

• None

Major Issues

• None

Minor Issues

• After performing NearZenith Focusing, the Job Execution had to wait 20 minutes until the allotated start time for first target (T CrB). By the time of the allotated start time, the target failed due to cloud and had to be resubmitted as a ToO target. Unclear why the start times were messed up. AutoStart began execution at 22:38, and planned Observing Plan was created at 22:41, with a required starting time of 26.4 minutes ahead of a Start Time of 23:24.. During the Starting phase the following expecting timings were listed at 22:43.:  
  Prepare Expected Timings              2026-07-26 22:43  (Local, BST)   
  Now                         Info      2026-07-26 22:43  (T -38 mins )  (SunAlt -7.18°)  
  Expected Shutter Opening    Info      2026-07-26 22:59  (T -22 mins )  (SunAlt -8.37°)   
  Expected Equilbrat'n Start  Info      2026-07-26 23:00  (T -21 mins )  (SunAlt -8.44°)   
  Expected Run Start          Info      2026-07-26 23:05  (T -16 mins )  (SunAlt -8.79°)   
  Expected Near-Zenith Foc1   Info      2026-07-26 23:08  (T -14 mins )  (SunAlt -8.96°)   
  Expected Near-Zenith Foc2   Info      2026-07-26 23:16  (T  -6 mins )  (SunAlt -9.48°)   
  Expected Queue Start        Info      2026-07-26 23:22  (T0         )  (SunAlt -9.86°)   
  Plan Queue Start            Info      2026-07-26 23:24  (Missed     )
  This shows that Queue was expected to start at T0 time of  23:22.   Shutter was opened 22:44 (15 mins ahead of expected time). at Near Zenith Focusing was successfully conducted between 22:45 and 22:59, finishing 25 minutes ahead of expected time. Target 1/13 (T CrB) was started at 22:59 but was unable to immediately commence , and execution when into a 20 minute wait loop, until 23:19 (5 minutes ahead of planned start time 23:24). Execution seems to have following design, in particular  the 20 minute pause ahead of T CrB corresponds to how target start times are meant to be used.  The situation appears to be related to AstroMain using the user defined AutoStart Reference of Sun Alt -9.0 deg, and AutoStart Window Start of SunAlt -9.0 deg + 30 mins (ie 22:38). Whilst appropriate for mid-summer (May-June) the AutoStart Reference needs to be modifed for late July.  AutoStart Reference changed on 2026-07-29 to SunAlt -10 deg - 20 mins.
  Closed after review  2026-07-27 (AstroMain)
   
• There is a discrepency in labelling of time on Weather Charts. Weather charts are designed to display and label data in local time.  Whilst the CloudSensor data displays data in BST , weather station data and cloudsensor rain charts appear to be showing data that is shifted by 1 hour. This is most evident when comparing rain data. CloudSensor file (CloudSensor_Data-2026-07.csv) has UT timestamps, and cloud sensor plot is correctly in BST local time (See Fig 1).  The CloudSensor Rain chart (Fig 2) and possibly also the WeatherStation Rain Chart (Fig 3) have data that is being plotted 1 hour too late suggesting that the 1 hour correction from UT to BST time is being applied twice. Fig 1b shows the 'truth' with data plotted against raw UT time.  Bug fixed in AstroWeather 1.30.4 (see Fig 2b & Fig 3b).
  Fixed 2026-07-28+ (AstroWeather 1.30.4)

Small Defects

• Fast Metaframe Snapshots files aren't using Local Time timestamp.  Fast Metaframe Snapshot file that were introduced recently are being created with filename timestamps using UT times.  They should be created using local time timestamps.
  Fixed 2026-07-27 (AstroNorthCam 1.10.3)
   
• Creation of Standard NorthCam Videos (Sunset, Night, Sunrise, Day) is failing. Following a change in AstroNorthCam 1.10.3 to introduce alternative Frame Rate videos the creation of standard videos began to fail on 2026-07-29 / 2026-07-30.  Logs showed that standard videos were likely failing as videos were being attempted with a VideoFrameRate of 0,  this was due to global VideoFrameRate wasn't being set in BuildStandardVideo(). Fixed in AstroNorthCam 1.10.4.
  Fixed 2026-07-30 (AstroNorthCam 1.10.4)

Continuous Improvement

• Modify AstroNorthCam's 'Create Video' routine to produce video using alternative frame rates.  AstroAllSky is able to create videos with frame rates of 1, 5, 10, 15 & 20 fps (where is Live Frame Rate).  AstroNorthCam 1.10.2 is currently only able to create videos with 'live' frame rate of 10 fps. This made it difficult to create a video with a slower rate when trying to show a moving satellite on 'Fast' Metaframe Max frames from the 10 minute interval 01:40 to 01:50 (2026-07-26/27).
  Done 2026-07-27 (AstroNorthCam 1.10.3)

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Fig 1. AstroWeather Graph - 18h CloudSensorPlot (GraphID=5)

Start of the 2 main rain intervals are correctly plotting at 04:15 and 09:02 Local Time (BST) and correspond to 03:15 and 08:02 UT in the data file (CloudSensor_Data-2026-07.csv).  

Code shows data is plotting using   'DataTime = CsData(i).DateX' and is compared against the PlotStartTime  #7/25/2026 05:00:00 PM# which is a UT time (17:00) corresponding to 18:00 BST.

Fig 1b  Excel Graph - 12 h Cloud Sensor Rain plotted from CloudSensor data file (time axis in UT)

This shows the 2 main rain intervals starting at 03:15 and 08:02 UT respectively.

Fig 2. AstroWeather Graph - 16h CloudSensor Rain (GraphID=84)

Start of the two main rain intervals are plotting at 05:15 and 10:02 Local Time (BST).  These are being plotted 1 hour too late. Hypothosis is that the 1 hour correction from UT to BST is being applied twice.

Code shows doesn't confirm the exact hypothesis,  but there is an extra ToLocalTime conversion in the code for GraphID=84  plotting that causes the bug.
  DataTime = CsData(i).DateX      Initially in UT
  DataTime = DataTime.ToLocalTime()    but then converted to BST
with DataTime then being compared against the PlotStartTime  ##7/25/2026 07:00:00 PM# # which is a UT time (19:00).

Fig 2b. AstroWeather Graph - 16h CloudSensor Rain  (GraphID=84) - Fixed

Rain data plotting correctly following bug fix 2026-07-29 in AstroWeather 1.30.4

 

Fig 3. AstroWeather Graph - 16h WeatherStation Rain (GraphID=79)

Start of the two main rain intervals are plotting at 05:15 and 10:30 Local Time (BST).  These seem to be being plotted 1 hour too late,  whilst there is a light possibility that WeatherStation rain could have a delay examination of code confirmed that plotting of weather station data suffers from the same bug as the CloudSensor Rain.



Fig 3b. AstroWeather Graph - 16h WeatherStation Rain (GraphID=79) - fixed

Rain data plotting correctly following bug fix 2026-07-29 in AstroWeather 1.30.4

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