David's Astronomy Pages
Notes - Session 827 (2020-11-05)

 
Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
 
Bullet Operational Issues
  - Critical Issues (0),  Major Issues (1),  Minor Issues (12),  Continuous Improvement (4)
Bullet Images from 2020-11-05 >>
Bullet Investigation - Slew Failure (Invalid RA)
 

Session Aims & Highlights (2020-11-05)

Main aims -

  1. Cam1 Guiding. Test routines and settings for guiding using LX200/ST10 (main scope, north down images) whilst imaging with TS80/178MC (secondary scope)
  2. Targets.  Acquire images of a selection of deep sky targets
  3. Bug fixes.  Check that bugs discovered in last session in AstroMain 3.31.2 have been fixed, and that recent new features are working ok

Equipment & Software

Highlights

Summary Plots & Logs

Observing Plan
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Observing Result
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Dome & Scope Slewing Performance
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Slew/Centering Performance
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Guiding Performance
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Sky Conditions (Locate Frames)
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Night Sky Summary Plot
Top axis: Sky Brightness at Zenith (in ADU/s)
Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)
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Pre-Session Weather Forecast (API data from darksky.net)
Pre-Session Weather forecast showed a clear spell in middle of evening (cloud cover 0-23%) but clouding at 22:00 to 02:00 (cloud cover 54-78%) ,
becoming totally overcast from 02:00 onwards.  Minimum temperature 6 degC.
Wind becoming strong onwards dawn with potential rain (heavy rain forecast from 08:00 onwards)

In the event there was a clear spell from 18:00 to 20:10 but transparency and seeing were fairly poor, and sky
was bright due to moonlight and cloud reflection. Cloud thickened at 21:45 and session suspended.  
User intervention made to finish session at 23:30 due to  cloud and rain risk.
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Session Event Log
Time     Event Detail
18:13:23 Session Monitoring AutoStart monitoring for Live Session opportunity starting between 18:13 & 05:33
18:13:24 Session AutoStarting Session autostarting (18:13)
18:14:06   Camera1 Connected SBIG Camera Connected (set point -15°C)
18:14:08 Session Created Live Session Created (2020-11-05 S00827, ImageSaveNum: 827001)
18:14:10   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
18:16:03   Services Started Observatory Services started
18:16:12 Observatory (Auto) Observatory placed in Fully-Automated Mode
18:16:14 Session Pending Session pending (2020-11-05)
18:16:16 Session Initiating Session initiating (2020-11-05)
18:16:18   Plan Requested Observing Plan requested from AstroPlan (1.17)
18:17:51   Plan Loaded Observing Plan loaded to queue (2020-11-05 V1 BEST PLAN, Plan ID: 562)
18:17:54   Camera1 Connected SBIG Camera Connected (set point -15°C)
18:18:02   Telescope Connected Telescope Connected (TheSky6)
18:18:13 Session Equilibration Session ready for dome & camera equilibration
18:19:14   Dome Opened Dome opened (opening time 45s)
18:19:16 Session Running Session running
18:19:18   Queue Started Observing Queue started (48 targets selected)
18:20:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:24:18       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
18:27:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
18:27:51       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
18:30:15       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
18:32:10       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
18:32:27       Focusing Checked Foc2 Focusing Check Succeeded
18:32:32     Target Started (1/48) Target started (1/48, B107). Using SharpCap
18:34:50       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:37:54       Focusing Failed Foc1 Focusing Failed - failed QC check (Ambiguous)
18:50:19     Target Completed Target completed (1/48, B107)
18:50:22     Target Started (2/48) Target started (2/48, GCVS S Cyg)
18:50:25   Camera1 Connected SBIG Camera Connected (set point -15°C)
18:51:41   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
18:52:11   SoftSuspend Cancelled Soft Suspend is cancelled due to Improved Conditions
18:53:21       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:56:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 4)
19:06:03     Target Completed Target completed (2/48, GCVS S Cyg)
19:06:05     Target Started (3/48) Target started (3/48, GCVS BL Lac)
19:09:37       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:12:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 5)
19:16:13     Target Completed Target completed (3/48, GCVS BL Lac)
19:16:16     Target Started (4/48) Target started (4/48, GCVS DY Per)
19:20:01       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:23:14       Focusing Completed Foc1 AutoFocus Completed (Profile No 6)
19:27:41     Target Completed Target completed (4/48, GCVS DY Per)
19:27:43     Target Started (5/48) Target started (5/48, GCVS HH And)
19:30:37       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:33:32       Focusing Completed Foc1 AutoFocus Completed (Profile No 7)
19:35:41     Target Completed Target completed (5/48, GCVS HH And)
19:35:43     Target Started (6/48) Target started (6/48, GCVS Z And)
19:38:39       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:41:30       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
19:45:17     Target Completed Target completed (6/48, GCVS Z And)
19:45:19     Target Started (7/48) Target started (7/48, GCVS AM Her)
19:49:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:52:14       Focusing Completed Foc1 AutoFocus Completed (Profile No 9)
19:56:11     Target Completed Target partially completed (7/48, GCVS AM Her)
19:56:13     Target Started (8/49) Target started (8/49, NGC 514, ToO)
19:59:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:02:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 10)
20:19:12     Target Completed Target completed (8/49, NGC 514, ToO)
20:19:14     Target Missed (9/49) Target's time slot was missed (9/49, WDS GRB 34)
20:19:16     Target Missed (10/49) Target's time slot was missed (10/49, GCVS U And)
20:19:18     Target Started (11/49) Target started (11/49, M31_AT2020vak)
20:21:48       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:25:01       Focusing Completed Foc1 AutoFocus Completed (Profile No 11)
20:36:09     Target Completed Target completed (11/49, M31_AT2020vak)
20:36:11     Target Started (12/49) Target started (12/49, C/2019 K7 (Smith))
20:49:54     Target Completed Target completed (12/49, C/2019 K7 (Smith))
20:49:56     Target Started (13/49) Target started (13/49, NGC 772)
20:52:52       Focusing Failed Foc1 Focusing Failed - unable to find a star (TCF-S)
21:10:07     Target Completed Target completed (13/49, NGC 772)
21:10:09     Target Started (14/49) Target started (14/49, GCVS TT Ari)
21:12:31       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:15:37       Focusing Completed Foc1 AutoFocus Completed (Profile No 12)
21:21:51     Target Completed Target completed (14/49, GCVS TT Ari)
21:21:53     Target Started (15/49) Target started (15/49, C/2018 N2 (ASASSN))
21:25:13       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:28:10       Focusing Completed Foc1 AutoFocus Completed (Profile No 13)
21:39:06     Target Completed Target completed (15/49, C/2018 N2 (ASASSN))
21:39:08     Target Started (16/49) Target started (16/49, GCVS RR Tau)
21:42:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:44:59       Focusing Completed Foc1 AutoFocus Completed (Profile No 14)
21:51:01     Target Completed Target completed (16/49, GCVS RR Tau)
21:51:03     Target Started (17/49) Target started (17/49, GCVS TT Ari)
21:53:34       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:56:41       Focusing Completed Foc1 AutoFocus Completed (Profile No 15)
22:02:54     Target Completed Target completed (17/49, GCVS TT Ari)
22:02:56     Target Started (18/49) Target started (18/49, GSC 1224:29)
22:05:20       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:08:33       Focusing Completed Foc1 AutoFocus Completed (Profile No 16)
22:14:19     Target Completed Target completed (18/49, GSC 1224:29)
22:14:21     Target Started (19/49) Target started (19/49, C/2019 L3 (ATLAS))
22:18:21     Target Failed Target failed due to slew error (19/49, C/2019 L3 (ATLAS))
22:22:46     Target Started (20/49) Target started (20/49, 61 Cyg)
22:22:48     Target Failed Target failed due to slew error (20/49, 61 Cyg)
22:29:50     Target Started (21/49) Target started (21/49, GCVS CI Cyg)
22:29:52     Target Failed Target failed due to slew error (21/49, GCVS CI Cyg)
22:38:33     Target Started (22/49) Target started (22/49, GCVS SS Cyg)
22:38:35     Target Failed Target failed due to slew error (22/49, GCVS SS Cyg)
22:53:45     Target Started (23/49) Target started (23/49, NGC 514)
22:56:37       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:58:40       Focusing Completed Foc1 AutoFocus Completed (Profile No 17)
23:09:42     Target Completed Target completed (23/49, NGC 514)
23:14:42     Target Started (24/49) Target started (24/49, GCVS ER UMa)
23:18:12       Focusing Failed Foc1 Focusing Failed - star is too dim (TCF-S)
23:23:28     Target Completed Target completed (24/49, GCVS ER UMa)
23:23:30     Target Started (25/49) Target started (25/49, UGC 6930)
23:27:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:29:18       Focusing Completed Foc1 AutoFocus Completed (Profile No 18)
23:40:20     Target Completed Target completed (25/49, UGC 6930)
23:40:22     Target Started (26/49) Target started (26/49, GCVS RX And)
23:43:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:45:46       Focusing Completed Foc1 AutoFocus Completed (Profile No 19)
23:48:21     Target Completed Target completed (26/49, GCVS RX And)
23:48:23     Target Started (27/49) Target started (27/49, GCVS FO Ori)
23:52:13       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:54:08       Focusing Failed Foc1 Focusing Failed - failed QC check (Ambiguous)
23:58:03     Target Completed Target completed (27/49, GCVS FO Ori)
23:58:05     Target Started (28/49) Target started (28/49, GCVS GK Per)
00:01:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:03:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 21)
00:06:05     Target Completed Target completed (28/49, GCVS GK Per)
00:06:07     Target Started (29/49) Target started (29/49, GCVS CM Tau)
00:08:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:10:16       Focusing Completed Foc1 AutoFocus Completed (Profile No 22)
00:23:46     Target Completed Target completed (29/49, GCVS CM Tau)
00:24:46     Target Started (30/49) Target started (30/49, GCVS FU Ori)
00:27:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:29:14       Focusing Completed Foc1 AutoFocus Completed (Profile No 23)
00:31:54     Target Completed Target completed (30/49, GCVS FU Ori)
00:33:06     Target Started (31/49) Target started (31/49, GCVS SU Tau)
00:35:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:37:15       Focusing Completed Foc1 AutoFocus Completed (Profile No 24)
00:41:28     Target Completed Target completed (31/49, GCVS SU Tau)
00:43:02     Target Started (32/49) Target started (32/49, GCVS NV Ori)
00:45:58       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:47:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 25)
00:51:11     Target Completed Target completed (32/49, GCVS NV Ori)
00:51:36     Target Started (33/49) Target started (33/49, NGC 2158)
00:53:43       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:55:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 26)
01:36:16     Target Completed Target partially completed (33/49, NGC 2158)
01:36:18     Target Started (34/49) Target started (34/49, Berkeley 37)
01:38:59       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:41:00       Focusing Completed Foc1 AutoFocus Completed (Profile No 27)
01:46:36     Target Completed Target completed (34/49, Berkeley 37)
01:46:38     Target Started (35/49) Target started (35/49, C/2019 Y4 (ATLAS))
01:49:39       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:51:49       Focusing Completed Foc1 AutoFocus Completed (Profile No 28)
02:13:24     Target Completed Target completed (35/49, C/2019 Y4 (ATLAS))
02:13:26     Target Started (36/49) Target started (36/49, Berkeley 76)
02:16:22       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:18:26       Focusing Completed Foc1 AutoFocus Completed (Profile No 29)
02:24:59     Target Completed Target completed (36/49, Berkeley 76)
02:25:01     Target Started (37/49) Target started (37/49, NGC 2324)
02:28:09       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:30:12       Focusing Completed Foc1 AutoFocus Completed (Profile No 30)
02:34:34     Target Completed Target completed (37/49, NGC 2324)
02:34:36     Target Started (38/49) Target started (38/49, Berkeley 26)
02:36:46       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:38:25       Focusing Completed Foc1 AutoFocus Completed (Profile No 31)
02:44:04     Target Completed Target completed (38/49, Berkeley 26)
02:44:45     Target Started (39/49) Target started (39/49, GCVS CN Ori)
02:47:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:49:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 32)
02:52:35     Target Completed Target completed (39/49, GCVS CN Ori)
02:53:56     Target Started (40/49) Target started (40/49, NGC 2232)
02:56:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:58:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 33)
03:38:42     Target Completed Target partially completed (40/49, NGC 2232)
03:38:44     Target Started (41/49) Target started (41/49, Nova AT2020bfc)
03:40:49       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:42:52       Focusing Completed Foc1 AutoFocus Completed (Profile No 34)
03:49:04     Target Completed Target completed (41/49, Nova AT2020bfc)
03:49:06     Target Started (42/49) Target started (42/49, Scholz's Star)
03:51:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:53:41       Focusing Completed Foc1 AutoFocus Completed (Profile No 35)
04:09:11     Target Completed Target completed (42/49, Scholz's Star)
04:09:13     Target Started (43/49) Target started (43/49, GCVS U Mon)
04:11:16       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
04:12:55       Focusing Completed Foc1 AutoFocus Completed (Profile No 36)
04:18:44     Target Completed Target completed (43/49, GCVS U Mon)
04:18:46     Target Started (44/49) Target started (44/49, LAMOST-HVS1)
04:20:39       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
04:22:46       Focusing Completed Foc1 AutoFocus Completed (Profile No 37)
04:25:56     Target Completed Target completed (44/49, LAMOST-HVS1)
04:28:30     Target Started (45/49) Target started (45/49, NGC 2782)
04:31:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
04:33:30       Focusing Completed Foc1 AutoFocus Completed (Profile No 38)
04:49:38     Target Completed Target completed (45/49, NGC 2782)
04:50:52     Target Started (46/49) Target started (46/49, NGC 3643)
04:54:21       Focusing Failed Foc1 Focusing Failed - star is too dim (TCF-S)
05:11:20     Target Completed Target completed (46/49, NGC 3643)
05:13:15     Target Started (47/49) Target started (47/49, GCVS SY Cnc)
05:15:38       Focusing Failed Foc1 Focusing Failed - star is too dim (TCF-S)
05:20:17     Target Completed Target completed (47/49, GCVS SY Cnc)
05:22:53     Target Started (48/49) Target started (48/49, GCVS RZ LMi)
05:27:05       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
05:28:54       Focusing Completed Foc1 AutoFocus Completed (Profile No 39)
05:33:48     Target Completed Target completed (48/49, GCVS RZ LMi)
05:34:41     Target Started (49/49) Target started (49/49, M61)
05:37:46       Focusing Failed Foc1 Focusing Failed - star is too dim (TCF-S)
05:54:39     Target Completed Target completed (49/49, M61)
05:54:42   Queue Completed Job Queue completed
05:54:44 Session Closing Session closing
05:55:39   Dome Closed Dome closed (closing time 50s)
05:56:05   Dome Parked Dome parked (parking time 18s), Az: 90.1 deg
05:56:53   Telescope Parked Telescope parked (parking time 40s)
05:57:23   Telescope Switched Off Telescope Power has been switched off via UPB Powerbox.
05:58:11   Services Stopped Night Services stopped
05:58:13 Session Housekeeping Housekeeping Started (Cleanup FITS, Create Fits Summary, Transfer Files)
05:58:44 Session Finished Session Finished
 
Session Alerts
Time     Alert Detail
18:51:43 Dome Discrepency Difference between Telescope Az and Dome Az is > 8 deg (GCVS S Cyg)

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Operational Issues (2020-11-05 S827)

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Critical Issues

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Minor Issues

Continuous Improvement

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Investigation - Slew Failure (Invalid RA)

Issue:
TheSky6 encountered an exception during slew to Target 22/49 (SS Cyg) and produced a modal error dialog which blocked further session progress until the dialog was manually acknowledged. 

Description: 
Target 24/49 was noted to be showing a slew failure when session progress was checked. A modal dialog window (with a TheSky6 icon in taskbar) was entitled "ASCOM.DeviceHub" and read "SlewToCoordinatesAsync: set '-0.0155881..' is an invalid value. The valid range is: 0 to 24." suggesting an issue with the RA coordinate.   DeviceHub and AstroMain User Interfaces remained active (no lock up or hang)

A brief look at the log file records "Exception during Telescope Slew" at 22:38:33.49 with the exception message "Command in progress   Error code = 219 (0xdb)". This was within 10ms of the command to Slew.  The target coordinates for the slew were   RA= 21 43 29.782 Dec= +43 40 21.06 | Epoch Current, so it's hard to see how the invalid RA value was given to TheSky since the routine operates perfectly fine for targets before and after SS Cyg.  The coordinates correspond to Az 274.2 / Alt= 52.4 which is a perfectly normal/valid sky position for a slew. Pre-Slew coordinates were   Ra= 02 53 45.000 Dec=+16 45 42.00 Epoch Current. Code needs to be examined to see how it might have been possible for RA 21 43 29.782 (21.0.7249394) to be converted to a value of -0.155881 for the slew and why on just this occasion.  Although the Slew failure was recorded as a 'Red' Session Event it should also have been recorded as a Red Session Alert & Alarm. 
 
In-Session Fix
After acknowledging the error (by clicking on dialog window's Ok button), the session automatically resumed without further incident.

Investigation:  
Investigating further showed that SS Cyg was the in fact the 4th of 4 consecutive targets that failed with a slew error.  Three of the targets including SS Cyg had failed with the "Command in progress, Error Code=219" but this was just the sideproduct of an open dialog window associated with a slew failure exception from the first of these targets ( Target 19/49 (C/2019 L3 Atlas) ).   Looking through the logs it feasible to understand how the issue occurred. 

The target had object coordinates of  RA= 23 59 41.513 Dec= +64 10 37.56 | Epoch 2000, which has current epoch coordinates of RA= 00 00 46.443 Dec= +64 17 43.67.   On top of this there was a slew adjustment of 1.48 arc min (W= 1.28', N= -0.76') giving slewing coordinates of RA= 00 00 34.712 Dec= +64 16 58.27.  (Coords need to be double checked in case any of them were in fact negative, but the logs don't indicate this as present). 

 After calling TheSky6's TeleASCOM.SlewToRaDec command the telescope targets would have received an additional adjustment form the TPoint Model. It is presumed that the routine for doing this in TheSky contains a bug that led to a negative and invalid RA coordinates which were blocked and raised as an exception.    '-0.0155881 would be equivalent to  - 00 00 56.12.  Given that target was of 00 00 34.712, equivalent to +0.0096422 the angular difference is only 22 arc min which would be well within the bounds of a T Point correction.  

Conclusion:
In rare cases of a target very close to RA 0 or RA 24, a bug in TheSky6 can allow a RA value to be generated and sent to telescope which is outside the range 0 to 24. 

Fix:
With the impossibility of obtaining a fix to TheSky6 as it is no longer supported by Software Bisque and it being unreasonable to ask Device Hub to be modified to accept -0.0155881 and convert it to 24-0.0155881, a workaround is necessary.

One 'fix' would be a modification of AstroMain (and even AstroPlan) code to either not schedule targets that are very close to RA 0 / RA 24 and prevent the target from attempting a slew to a target that is very close to RA 0 / Ra 24. However such targets would simply not be able to acquired. 

The proposed alternate 'fix' is to slew to targets that close to RA 0 / RA 24 using ASCOM Telescope.SlewToCoordinatesASync command instead of using the TheSky. Telescope.SlewToRaDec command.  This would prevent potential invalid RA coordinates from causing an Out of Range exception that blocks automated Telescope operation viaTheSky6, but would miss out on the more accurate slewing that can be achieved with a TPoint model. The latter loss can be largely mitigated by target centering operations (taking a locate frames, plate solving it and making the appropriate jog correction(s))

AstroMain Scope.SlewTheSkyScope routine has been modified to using DeviceHub.Telescope.SlewToCoordinatesASync when target RA < 0.04 or RA > 24 - 0.04
Image Fixed 2020-11-06 (AstroMain 3.32.4)

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