David's Astronomy Pages Notes - Session 1361 (2025-09-11)

Notes (S1360)

Notes Main

Home Page

Notes (S1362)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (1),  Minor Issues (0),  Small Defects (3),  Continuous Improvement (3)
	- Figures (2)
	Images from 2025-09-11  >>
	New Master Flats - C Filter (2025-09-12)

Session Aims & Highlights (2025-09-11)

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.

 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 3.77.12,  AstroPlan 1.43.12, AstroShCap 1.3.16, 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 1.27.10, AstroAllSky 3.24.6,  AstroObsCam 1.11.7, AstroNorthCam 1.6.1, AstroLaunch 1.13.6

Highlights

• Targets. 7/27 planned targets were successfully completed with 1 target partially completed. Other targets failed due to cloud / session suspension, of which 3-4 target slots were in-filled by 4 ToO targets (C/2023 A3 (Tsuchinshan-ATLAS) , NGC 7094, NGC 7128, KIC 8462852)
• 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

• Flat frames taken for C Filter following the session and the resulting new master flats were used for Image Reduction of images from the session
  (see New Master Flats - C Filter (2025-09-12) ).
  

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 21:02:09 Session Monitoring AutoStart monitoring for Live Session opportunity between 21:02 & 04:43 21:02:11 Session AutoStarting Session autostarting (21:02) 21:02:23   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 21:02:38 Session Created Session Created (Live, 2025-09-11 S01361, ImageSaveNum: 1361001) 21:02:45   Scope Switched On Telescope Power has been switched on via UPB Switch 21:04:32   Services Started Observatory Services started 21:04:41 Observatory (Auto) Observatory placed in Fully-Automated Mode 21:04:46 Session Pending Session pending (2025-09-11) 21:04:48 Session Initiating Session initiating (2025-09-11) 21:05:07   Camera1 Connected SBIG Camera connected (Set point -10°C) 21:05:10   Plan Requested Observing Plan requested from AstroPlan (1.43.14) 21:05:39   Plan Loaded Observing Plan loaded to queue (Plan ID: 1147) 21:06:22   Telescope Connected Telescope connected (TheSky6) 21:06:46 Session Equilibration Session ready to Open Dome 21:07:31   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 21:08:11 Session Running Session running 21:08:14   Queue Started Observing Queue started (27 targets selected) 21:08:17     Target Started (NrZen) Target started (Focus Field 19, HIP 93376) 21:08:32       Dome Unparked Dome unparked 21:11:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 21:13:40       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide) 21:15:40       Focusing Completed Foc1 AutoFocus Completed (Profile No 1) 21:15:42       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 21:17:20       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 21:19:00       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 21:19:20     Target Completed (NrZen) Target completed (Focus Field 19, HIP 93376) 21:21:38     Target Started (1/27) Target started (1/27, NGC 4475 w/SN2025nat) 21:23:34     Target Aborted (1/27) Target aborted (1/27, NGC 4475 w/SN2025nat) due to Priority 1 ToO Target 21:23:38     Target Started (2/28) Target started (2/28, C/2023 A3 (Tsuchinshan-ATLAS), ToO) 21:30:45       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 21:32:37       Focusing Completed Foc1 AutoFocus Completed (Profile No 3) 21:39:14     Target Completed Target completed (2/28, C/2023 A3 (Tsuchinshan-ATLAS), ToO) 21:43:38     Target Started (3/28) Target started (3/28, T CrB) 21:46:51       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 21:49:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 4) 21:53:08     Target Completed Target completed (3/28, T CrB) 21:54:34     Target Started (4/28) Target started (4/28, Nova Ser 2025) 21:58:42       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:01:14       Focusing Completed Foc1 AutoFocus Completed (Profile No 5) 22:07:11     Target Completed Target completed (4/28, Nova Ser 2025) 22:07:15     Target Started (5/28) Target started (5/28, NGC 5957 w/SN2025fvw) 22:10:18     Target Aborted (5/28) Target aborted (5/28, NGC 5957 w/SN2025fvw) due to Priority 1 ToO Target 22:10:22     Target Started (6/29) Target started (6/29, NGC 7094, ToO) 22:14:05       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:16:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 6) 22:24:56     Target Completed Target completed (6/29, NGC 7094, ToO) 22:29:15     Target Started (7/29) Target started (7/29, UGC 10809 w/SN2025vaw) 22:32:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:34:45       Focusing Completed Foc1 AutoFocus Completed (Profile No 7) 22:50:43     Target Completed Target completed (7/29, UGC 10809 w/SN2025vaw) 22:51:34     Target Started (8/29) Target started (8/29, UGC 10717 w/SN2022ybd) 22:54:57       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 22:57:24       Focusing Completed Foc1 AutoFocus Completed (Profile No 8) 23:04:11       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 23:05:21       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions 23:13:20     Target Completed Target completed (8/29, UGC 10717 w/SN2022ybd) 23:13:24     Target Started (9/30) Target started (9/30, NGC 7128, ToO) 23:17:33       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:19:59       Focusing Completed Foc1 AutoFocus Completed (Profile No 9) 23:24:11     Target Completed Target completed (9/30, NGC 7128, ToO) 23:24:15     Target Started (10/31) Target started (10/31, KIC 8462852, ToO) 23:27:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 23:29:43       Focusing Completed Foc1 AutoFocus Completed (Profile No 10) 23:33:28     Target Completed Target completed (10/31, KIC 8462852, ToO) 23:33:30     Target Missed (11/31) Target's time slot was missed (11/31, AT2025kyz) 23:35:54     Target Started (12/31) Target started (12/31, 2MFGC 13744 w/SN2024afyu) 23:40:22       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI) 23:50:37       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 23:51:47       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions 23:54:48       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 23:55:43       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions 23:56:27     Target Completed Target completed (12/31, 2MFGC 13744 w/SN2024afyu) 23:58:14     Target Started (13/31) Target started (13/31, Vega) 00:03:13     Target Completed Target completed (13/31, Vega) 00:05:40     Target Started (14/31) Target started (14/31, GCVS RR Lyr) 00:08:36       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:10:07       Focusing Failed Foc1 focusing failed - star lost 00:18:50     Target Completed Target completed (14/31, GCVS RR Lyr) 00:20:24     Target Started (15/31) Target started (15/31, Vega) 00:25:20     Target Completed Target completed (15/31, Vega) 00:27:51     Target Started (16/31) Target started (16/31, M31 w/Nova M31 AT2025wwe) 00:31:40       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:33:51       Focusing Completed Foc1 AutoFocus Completed (Profile No 12) 00:50:26     Target Completed Target completed (16/31, M31 w/Nova M31 AT2025wwe) 00:50:30     Target Started (17/31) Target started (17/31, GCVS U And) 00:53:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:55:28       Focusing Completed Foc1 AutoFocus Completed (Profile No 13) 01:00:06       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 01:01:16   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 01:01:18   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 01:01:23     Target Aborted (17/31) Target aborted (17/31, GCVS U And) due to cloud 01:01:25   Queue Paused Queue paused for Session Suspension 01:01:29 Session Suspending Session suspending 01:02:16   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 01:02:19 Session Suspended Session suspended 01:05:02     Target Cancelled Target cancelled (17/31, GCVS U And) due to cloud 01:18:43     Target Cancelled Target cancelled (18/31, GCVS TT Ari) due to cloud 01:30:48     Target Cancelled Target cancelled (19/31, AT2022obq (CV)) due to cloud 01:50:48     Target Cancelled Target cancelled (20/31, AT2023mil) due to cloud 02:12:48     Target Cancelled Target cancelled (21/31, AT2025rkp) due to cloud 02:26:48     Target Cancelled Target cancelled (22/31, AT2023ehg (CV)) due to cloud 02:37:06     Target Cancelled Target cancelled (23/31, KIC 8462852) due to cloud 02:57:06     Target Cancelled Target cancelled (24/31, AT2025kjq) due to cloud 03:09:24     Target Cancelled Target cancelled (25/31, GCVS BL Lac) due to cloud 03:29:24     Target Cancelled Target cancelled (26/31, AT2025vel) due to cloud 03:51:44     Target Cancelled Target cancelled (27/31, AT2022xao) due to cloud 04:05:46     Target Cancelled Target cancelled (28/31, GCVS DX Cnc) due to cloud 04:28:16     Target Cancelled Target cancelled (29/31, C/2025 A6 (Lemmon)) due to cloud 04:48:36     Target Cancelled Target cancelled (30/31, NGC 2744 w/SN2025oq) due to cloud 05:10:54     Target Cancelled Target cancelled (31/31, GCVS ER UMa) due to cloud 05:10:58   Queue Completed Job Queue completed 05:11:02 Session Closing Session closing 05:11:07   Dome Closed Dome already closed (closed at 01:02, closing time 50s, zigbee 43s) 05:11:35   Dome Parked Dome parked (parking time 20s), Az: 90.0 deg 05:12:20   Telescope Parked Telescope parked (parking time 41s total) 05:12:44   Telescope State Handbox reads 'Scope parked Turn scope off.' 05:13:06   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 05:14:29   Services Stopped Night Services stopped 05:14:32 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 05:14:54     Dome (Find Park) Find Park started (Search Az 80.0 to 100.0°, Step 1.0°, Wide) 05:15:31     Dome Find Park found (Best Park Az 86.0°) 05:15:37     Dome (Find Park) Find Park started (Search Az 84.0 to 88.0°, Step 0.2°, Narrow) 05:16:21     Dome Find Park found (Best Park Az 86.2°) 05:16:27     Dome Dome has been synced at park position (Az 90.0°, Adjustment: +3.8°) 05:16:29   Dome Parked Dome parked 05:16:37   Dome Charging Dome is parked and re-charging Ok (17mA) 05:16:39 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 05:16:37 Green Clear Dome Charging Dome is parked and re-charging Ok (17mA)

Back to Top

Operational Issues (2025-09-11 S1361)

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

Critical Issues

• None

Major Issues

• Rain Sensor seems to have developed a fault with rain value of -197.3 to -197.6 (2025-09-11 00:21 UT). Throughout the session rain values coming from the Eurotech Cloud/Rain Sensor were noted to be anomalous with values reading -197.3 to -197.6  when the normal value when it isn't raining is -0.9 to -0.1. Since the value was less than 0.3 ObsManager took the conditions to be dry and allowed the session to proceed. Similarly since the value was less than 1.0 the Dome Relay wasn't triggered and the dome shutter wasn't forced to close that would have prevented the session from proceeding..  Clarity valuues and lIght values were normal. With no rain in the weather forecast the session had allowed to proceed, however this on the basis that there were be no direct rain protection for the Observatory (apart from Rain Threat information from minutely Weather API data , and the usual low clarity (cloudy sky)  protection.  The same rain values were reported even after power cycling the Cloud/Rain Sensor. Checking the sensor head the following day failed to identify a reason for the anomalous rain value (e.g there was no sign of bird poo or other on sensor. A test show that the sensor would respond to water being tipped on the sensor, the sensor values rose to -137 and then fell back to -187), suggesting the sensor head has somehow lost its calibration, there is no way to reset / redo the calibration within the CloudSensor software. Examining rain sensor data showed that the fault started at 2025-09-11  00:21 UT, when values changed from 30 (wet) to -910 (anomaly) before rising firstly to 50  to -120  and then falling slowly to a new baseline of -197, as shown in Fig 1  (value eventually reached a level of -204 by 2025-09-15 (see Fig 2). A Working on the provisional basis that the rain sensor is still working and has the  relationship to rain amount but has simply loss its calibration is it possible to restore rain protection for the Observatory. The answer is yes and no.  It is feasible to add a master rain trim to AstroWeather to adjust the rain values by a set amount , to bring the used value close to 0.0 for dry conditions, however it is not possible to set a wet/drythreshold in the Sensor Head to less than -9, and therefore low level rain protection wouldn't be possible via the dome relay level.  Cloud Sensor III software was uninstalled and then reinstalled on 2025-09-16 but this didn't resolve the issue. 
  { In regard to getting a replacement , the Eurotech Cloud Sensor III is currently out of stock due to component supply issues}
  A MasterRainTrim field has been added to AstroMain's More/AllSky Tab in v3.77.15 and used to correct 'Raw Rain' value to 'Rain' value, using equation
    Corrected Rain = Rain + 197
  A MasterRainTrim field has similarly added to AstroWeather's Settings Tab in v1.27.11 and AstroAllSky's More Tab ib v3.24.7.  The 'raw' rain value for dry and for wet conditions were monitored over the next 5 days to see if how values vary. After further data and seeing the rain sensor value during period of heavy rain during the night 2025-09-14 / 2025-09-15 (see Fig 2) a new correction equation was established
    Corrected Rain = ( Rain + 200 ) * 0.25
  This was incorporated in AstroWeather 1.28,  AstroAllSky 3.25, AstroMain 3.78 & AstroGuard 1.12. A separate Continuous Improvement ticket has been added to purchase a new Eurotech Cloud Sensor II in order to regain low level rain protection for Observatory via Dome Relay. However this is on hold.as the product is currently out of stock at Euotech due to component supply issues}
  Fixed via workarounds 2025-09-16 (Eurotech Cloud/Rain Sensor, AstroWeather 1.28,  AstroAllSky 3.25, AstroMain 3.78 & AstroGuard 1.12.)

Minor Issues

• None

Small Defects

• Following the session AstroMain's SBIG Camera status field is showing "Connected", even though the Camera is not actually connected (05:13). When checked the following morning the SBIG Camera Status field was showing "Connected" with lime green background whilst the Camera Status in CCDSoft is showing the camera as being disconnected. AstroMain Report File from the session clearly show the camera being disconnected at end of session.  It is believed that this issue was reported before and supposedly fixed ?.  The issue doesn't happen when the 'Close' (Camera) button is used to close down the camera.  When ObsManger closes the camera during ClosingStage 14 the CloseDownCamera2() routine is used, whilst when the User closes the camera via Button  the CloseDownCamera() is routine. Fixed in AstroMain 3.77.13, the appropriate calls to objConsole.txtCameraState.Text = "Not-Connected" and objConsole.txtCameraState.BackColor = Color.Salmon have been added to the CloseDownCamera2() routine.
  Fixed  2025-09-12 (AstroMain 3.77.13)
   
• With the SBIG Camera not connected a snap image was permitted to be started. Checks should be made and if camera is not connected, the operation shouldn't be permitted. When action is from user button an appropriate message shown be shown.  Fixed in AstroMain 3.77.13.
  Fixed  2025-09-12 (AstroMain 3.77.13)
   
• No target circles were drawn on realtime JPG pictures for UGC 10809 w/SN2025vaw (22:35). The expected blue circle showing the respective target position was missing from Focus and Main Frame JPG pictures for Target 7/29 (UGC 10809 w/SN2025vaw , id=3614 , #1361045 et al). This is the precisely the same issue that affected 3 targets in session S1358, where it was ascertained that the issue occurs in   situations where just a single Locate Frame is taken and where the issue can't be replicated on playback on the Development Computer (see S1358 notes) Additional tracing was added in AstroMain 3.77.12  to dump coordinates in LocateInfo.BrightestStars() prior to making MatchStars attempt to see if/how the list has changed since it was set during Locate 1 operation. In the new case (UGC 10809 w/SN2025vaw ), the trace statements show that the LocateInfo.BrightestStars() coordinates are present and normal which eliminates one potential cause of the issue.  Code to be reexamined and if bug can't be found, to add more tracing. The difficulty with this issue is that it can't be replicated upon playback/test run on Development Computer but consistently occurs during live sessions on the Observatory Computer.  Does the issue occur during Playback/test run on the Observatory Computer ?.  One hypothesis is that Image Inventory was showing prior to calling Calculate ImageShift() routine, but the ShowInventory() call prior to getting inventory data turned off the Inventory, resulting in 'old' or 'null' inventory array information (e.g. arrays associated Cam2 Reference Frame)  and hence no matches to LocateInfo's Brighest Stars points could be made. Extra tracing added to AstroMain 3.77.14 to try to determine if this hypothesis is valid.  A new global variable 'nLocateFramesTaken' has been added that is set during Target Centering and used by CalculateImageShift with further conditional tracing when  'nLocateFramesTaken=1', and a potential 'fix' has been added that can force Inventory to be shown or at least not hidden. The new code with latest racing & potential fix was executed under live session conditions in session S1363 (2025-09-16) but the one case with a single Locate Frame showed that the issue still remains.
  To fix 2025-09-17+ (AstroMain 3.78+)

Continuous Improvement

• When 'Turn Off ObsCam' and 'Turn On ObsCam' buttons are used from AstroMain's More/AllSky Tabs appropriate report and log messages should be written. Currently in AstroMain 3.77.12 and earlier versions there is no acknowledge that eithe 'Turn Off ObsCam' and 'Turn On ObsCam' buttons have been activated and the request has been sent to AstroObsCam on the AllSky/Weather Computer.  Implemented in AstroMain 3.77.14
  Done 2025-09-12 (AstroMain 3.77.14)
   
• Consider how AstroObsCam could use stacked image to improve S/N of a picture taken under low light conditions.  The quality of ObsCam pictures taken under nighttime low light conditions (as opposed to those taken under Aux Light Conditions or Daylight Conditions) could be improved by stacking several frames together. How could this be achieved. Images are JPG pictures not FITS images and the change likely requires a significant modification to how frames are current acquired / processed / annotated. .
  On Hold 2025-09-12 (AstroMain 3.77.13)
   
• Purchase a new Eurotech Cloud Sensor III in order to regain low-level rain protection for the Observatory via Dome Relay.  A fault has been developed in the Cloud Sensor III such that the Rain Sensor is no longer calibrated to give value of -1 to 0 for Dry Condition and instead gives values of -197 to -205 (see Fig 1).  Problem can't be resolved by restting the Sensor Head or reinstalling Cloud Sensor III software.  Since the Sensor Head can't be set to have a Dry/Wet threshold of less than -9 it is not possible to set a value of -200 which means that the Sensor Head isn't able to alter the Relay state when it is raining (values -190 to -30) meaning that there is no low level rain protection for the Observatory via the Dome Relay. Protection hasto be provided a higher level involving AstroMain & AstroAllSky/AstroGuard.  It is proposed to purchase a new Eurotech Cloud Sensor III in order to regain low level rain protection via Dome Relay. However this is on hold.as the product is currently out of stock at Euotech due to component supply issues. Alternative sensors may be available, but none would seemlessly fit into the present Observatory system.
  On Hold 2025-09-16 (Eurotech Cloud Sensor)

[ Prev | Next ]

Back to Top Issue,  Back to Top

---

Fig 1.  Rain Sensor Failure 2025-09-10 / 2025-09-11

Fig 2. Rain Sensor Data 2025-09-10 to 2025-09-16

[ Prev | Next ]

Back to Top Issue,  Back to Top

---

New Master Flats - C Filter (2025-08-13)

Sets of New Flat Frames were acquired on 2025-07-30 using Light Board place in front of the LX200.  This was necessiatated by installation of new TCF-LSI focuser and recognition that it leads to a different vignetting levels compared to those using the prveious TCF-S focuser. and recognition that flat field / vignetting artefacts are seen if new images are flat field corrected using older master flats.

Flat Frames

Flat frames were acquired for each binning mode (3x3, 2x2 & 1x1) and for C filters held in the Filter Wheel., with CCD Tempearture operating at -5°C per the following table

Filter

Filter

3x3

2x2

1x1

Position

Name

n

Exp(s).

Sheets

n

Exp(s)

Sheets

n

exp(s)

Sheets

1

C

23

x

1.6s

(2)

23

x

3.5s

(2)

23

x

2.4s

(1)

Dark Frames

Dark frames were acquired with CCD Temperature operating at the same value of -5°C that the flat frames were acquired at.

3x3		0		23	x	1.6s
2x2		0		23	x	3.5s
1x1		0		23	x	2.4s

Master Frames

For each Dark Set the Dark Frames were stacked using AvMedian method in the Sigma Beta program. The Master Bias & Master Dark Frames generated were copied to the relevant subfolder (1x1 Masters, 2x2 Masters & 3x3 Masters) at 'C:\Data\CCD Imaging\Analysis\_Darks\-5c'

For each Flat Set the Flat Frames were reduced in CCDSoft using the Reduce Folder facility using the Flat Frame Reduction group and relevant master Dark and Master Bias Frames. Reduced flats from each set were then stacked using AvMedian method in Sigma Beta program. The Master Flats generated were copied to the relevant subfolder (1x1 Masters, 2x2 Masters & 3x3 Masters) at 'C:\Data\CCD Imaging\Analysis\_Flats'

Pictures below show the newly generated Master Flats for the C Filter, and are compared with the previous Master Flat.
The disappearance of one of the dust mottes on left hand side can clearly be seen.

Previous Master Flat, C filter (3x3) from S1347 (Average Median for 25 frames, 2025-08-13 )		New Master Flat, C filter (3x3) from S1361 (Average Median for 23 frames, 2025-09-12 )

Back to Top

---

This Web Page:	Notes - Session 1361 (2025-09-11)
Last Updated :	2025-11-19
Site Owner :	David Richards
Home Page :	David's Astronomy Web Site