Sky transparency — night of 5–6 October 2026

Cloud arrived at 22:06 — detected by the all-sky camera, independent of N.I.N.A. Before it the sky ran at index 100 (IQR 89–103); after it 100 (IQR 33–108). 15 of 33 light frames landed before the cloud. 87 of 87 failures are attributed to cloud. Guiding ran at 0.97″ RMS before the cloud and 2.92″ after; the worst minute was 11.22″ at 04:21. Morning sky flats: 63 frames (O 21, S 21, H 21), 06:44–06:48, auto-exposure 0.9–1.6 s.

Index before 22:06
100 · IQR 89–103
Index after 22:06
100 · IQR 33–108
Cloud onset (all-sky)
22:06 · independent
Errors after onset
87 of 87 · solve + PHD2
Guide RMS
1.99″ · RA 1.61 · Dec 1.17

Normalised transparency index, by filter

100 = that target and filter's own clear‑sky median (this night's own pre-cloud median). Shaded columns are autofocus runs; the first target is named at the top left and dashed vertical rules mark each target change; ticks along the base are errors.

H α O III S II ▲ Plate solve failed ◆ PHD2 error
05010015020021:0022:0023:0000:0001:0002:0003:0004:0005:0006:00% of clear-sky medianclear-sky baselineM 17→ M 17→ IC 434 Panel 1→ IC 434 Panel 1→ IC 434 Panel 1→ IC 434 Panel 2→ IC 434 Panel 3OHS

All‑sky background brightness

Mean luminance of the upper sky per all‑sky still — independent of anything N.I.N.A. recorded. The camera auto‑exposes, so this is an instrumental number, not photometry.

0408012016021:0022:0023:0000:0001:0002:0003:0004:0005:0006:00Mean sky luminance (0–255)all-sky

PHD2 guiding

RMS tracking error per minute from the PHD2 guide log, taken about zero rather than about each minute's mean, so slow drift counts as error. 1480 guide frames over 3.7 h of guiding in 23 sessions; the gaps are slews, dither settles and autofocus runs, when PHD2 was not guiding. PHD2 discarded 732 further frames — usually a lost star. The worst minute (11.22″ at 04:21) is clamped at the top of the plot.

RA RMS Dec RMS ◆ PHD2 error
0.01.22.43.64.821:0022:0023:0000:0001:0002:0003:0004:0005:0006:00RMS guide error (arcsec)night RMS 1.99″DecRA

All‑sky frames at the key moments

Times come from the still filenames, so they line up with the charts exactly.

All-sky at 20:28
20:28 · start of night
All-sky at 22:06
22:06 · cloud onset
All-sky at 22:15
22:15 · peak brightness 159.8
All-sky at 06:22
06:22 · end of night

Clear‑sky reference medians

The divisors behind the index — median detected stars per light sub before 22:06. IC 434 Panel 1 and IC 434 Panel 2 had no clear frames tonight and no clear history, so its divisor is its own whole-night median. Its index shows how the sky changed during that target, not how it compared with a clear sky.

TargetFilterMedian starsFramesSource
IC 434 Panel 1H34whole night, cloud included
IC 434 Panel 1O14whole night, cloud included
IC 434 Panel 1S14whole night, cloud included
IC 434 Panel 2H154whole night, cloud included
IC 434 Panel 2O652whole night, cloud included
M 17H3917tonight, clear frames
M 17O7354tonight, clear frames
M 17S11354tonight, clear frames

Event timeline

All observatory events with their attributed causes.

solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
AF failedautofocus run started 02:35:12 did not completecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
PHD2timed-out waiting for guider to settlecloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
AF failedautofocus run started 04:45:47 did not completecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
solve failedASTAP plate solve failedcloud
solve failedASTAP plate solve failedcloud
PHD2timed-out waiting for guider to settlecloud
All 248 frames (excludes the 63 sky flats — no stars to detect)
TimeClassTargetFilterExpStarsHFRIndex
20:28:22autofocusM 17L5s6442.97—
20:28:39autofocusM 17L5s4903.26—
20:28:54autofocusM 17L5s7442.31—
20:29:09autofocusM 17L5s9161.96—
20:29:24autofocusM 17L5s8572.23—
20:29:44autofocusM 17L5s6333.15—
20:30:04autofocusM 17L5s4943.75—
20:30:24autofocusM 17L5s3894.78—
20:30:44autofocusM 17L5s3694.33—
20:30:59autofocusM 17L5s2615.37—
20:31:19autofocusM 17L5s8372.11—
20:37:46lightM 17H300s3484.1789%
20:43:24lightM 17H300s3124.4080%
20:49:30lightM 17H300s4183.76107%
20:54:53lightM 17H300s4403.70113%
21:00:34lightM 17O300s6493.6688%
21:06:23lightM 17O300s6744.2192%
21:11:56lightM 17O300s7353.91100%
21:12:40autofocusM 17L5s6602.39—
21:12:59autofocusM 17L5s2585.80—
21:13:20autofocusM 17L5s3304.48—
21:13:39autofocusM 17L5s4463.47—
21:13:59autofocusM 17L5s6202.60—
21:14:19autofocusM 17L5s7662.20—
21:14:39autofocusM 17L5s8212.09—
21:14:59autofocusM 17L5s7332.47—
21:15:20autofocusM 17L5s6233.15—
21:15:40autofocusM 17L5s4344.12—
21:16:00autofocusM 17L5s3575.05—
21:16:19autofocusM 17L5s8192.10—
21:22:20lightM 17O300s7733.78105%
21:28:36lightM 17S300s9983.9588%
21:34:09lightM 17S300s11353.70100%
21:40:01lightM 17S300s11673.61103%
21:45:30lightM 17S300s10263.7990%
21:51:27lightM 17H300s3913.80100%
21:56:59lightM 17H300s3913.79100%
22:02:49lightM 17H300s3933.81101%
22:12:45centeringM 17L5s242.93—
22:21:39centeringM 17L0s00.00—
22:22:12centeringM 17L5s2313.68—
22:22:46centeringM 17L0s00.00—
22:24:45centeringM 17L5s00.00—
22:24:55centeringM 17L5s10.00—
22:25:05centeringM 17L5s220.32—
22:25:30centeringM 17L5s334.90—
22:25:40centeringM 17L5s434.12—
22:25:49centeringM 17L5s435.47—
22:30:15centeringM 17L5s00.00—
22:30:25centeringM 17L5s00.00—
22:30:35centeringM 17L5s00.00—
22:31:00centeringM 17L5s00.00—
22:31:09centeringM 17L5s10.00—
22:31:19centeringM 17L5s00.00—
22:32:45centeringM 17L5s00.00—
22:32:55centeringM 17L5s10.00—
22:33:05centeringM 17L5s10.00—
22:33:30centeringM 17L5s10.00—
22:33:40centeringM 17L5s10.00—
22:33:49centeringM 17L5s00.00—
22:35:10centeringM 17L5s236.93—
22:35:20centeringM 17L5s236.45—
22:35:29centeringM 17L5s236.71—
22:35:55centeringM 17L5s10.00—
22:36:05centeringM 17L5s241.39—
22:36:15centeringM 17L5s10.00—
22:38:15centeringM 17L5s10.00—
22:38:25centeringM 17L5s10.00—
22:38:35centeringM 17L5s231.33—
22:39:00centeringM 17L5s00.00—
22:39:10centeringM 17L5s00.00—
22:39:19centeringM 17L5s00.00—
22:40:30centeringM 17L5s629.53—
22:40:39centeringM 17L5s729.71—
22:40:49centeringM 17L5s729.88—
22:41:15centeringM 17L5s00.00—
22:41:26centeringM 17L5s10.00—
22:41:36centeringM 17L5s10.00—
22:43:20centeringM 17L5s10.00—
22:43:30centeringM 17L5s10.00—
22:43:40centeringM 17L5s10.00—
22:43:50centeringM 17L5s10.00—
22:44:00centeringM 17L5s00.00—
22:44:10centeringM 17L5s00.00—
22:44:20centeringM 17L5s00.00—
22:44:30centeringM 17L5s00.00—
22:44:40centeringM 17L5s00.00—
22:44:50centeringM 17L5s00.00—
22:45:00centeringM 17L5s00.00—
22:45:10centeringM 17L5s00.00—
22:45:20centeringM 17L5s00.00—
22:45:30centeringM 17L5s00.00—
22:45:40centeringM 17L5s00.00—
22:45:51centeringM 17L5s00.00—
22:46:01centeringM 17L5s00.00—
22:46:11centeringM 17L5s00.00—
22:46:22centeringM 17L5s00.00—
22:46:32centeringM 17L5s00.00—
22:46:42centeringM 17L5s00.00—
22:46:52centeringM 17L5s00.00—
22:47:03centeringM 17L5s00.00—
22:47:13centeringM 17L5s00.00—
22:47:24centeringM 17L5s00.00—
22:48:25centeringM 17L5s00.00—
22:48:35centeringM 17L5s00.00—
22:48:44centeringM 17L5s00.00—
22:49:10centeringM 17L5s00.00—
22:49:20centeringM 17L5s00.00—
22:49:30centeringM 17L5s00.00—
22:51:05centeringM 17L5s00.00—
22:51:14centeringM 17L5s00.00—
22:51:24centeringM 17L5s00.00—
22:51:50centeringM 17L5s00.00—
22:52:00centeringM 17L5s00.00—
22:52:10centeringM 17L5s00.00—
22:55:44autofocusM 17L5s3101.57—
22:55:58autofocusM 17L5s1114.60—
22:56:13autofocusM 17L5s1583.12—
22:56:28autofocusM 17L5s2312.15—
22:56:43autofocusM 17L5s3201.51—
22:57:03autofocusM 17L5s2981.60—
22:57:23autofocusM 17L5s2382.20—
22:57:43autofocusM 17L5s1393.31—
22:58:03autofocusM 17L5s994.37—
22:58:23autofocusM 17L5s635.69—
22:58:43autofocusM 17L5s785.88—
22:59:03autofocusM 17L5s2891.56—
23:19:50centeringIC 434 Panel 1L5s10.00—
23:19:59centeringIC 434 Panel 1L5s00.00—
23:20:09centeringIC 434 Panel 1L5s10.00—
23:20:25centeringIC 434 Panel 1L5s10.00—
23:20:35centeringIC 434 Panel 1L5s440.78—
23:20:44centeringIC 434 Panel 1L5s10.00—
23:22:05centeringIC 434 Panel 1L5s439.34—
23:22:14centeringIC 434 Panel 1L5s638.99—
23:22:23centeringIC 434 Panel 1L5s339.57—
23:22:40centeringIC 434 Panel 1L5s10.00—
23:22:49centeringIC 434 Panel 1L5s221.63—
23:22:58centeringIC 434 Panel 1L5s10.00—
23:24:10centeringIC 434 Panel 1L5s337.56—
23:24:19centeringIC 434 Panel 1L5s437.30—
23:24:29centeringIC 434 Panel 1L5s236.78—
23:24:45centeringIC 434 Panel 1L5s10.00—
23:24:54centeringIC 434 Panel 1L5s10.00—
23:25:04centeringIC 434 Panel 1L5s10.00—
23:26:25centeringIC 434 Panel 1L5s535.35—
23:26:35centeringIC 434 Panel 1L5s334.97—
23:26:44centeringIC 434 Panel 1L5s335.83—
23:27:10centeringIC 434 Panel 1L5s00.00—
23:27:20centeringIC 434 Panel 1L5s00.00—
23:27:29centeringIC 434 Panel 1L5s00.00—
23:28:55centeringIC 434 Panel 1L5s234.92—
23:29:05centeringIC 434 Panel 1L5s435.33—
23:29:14centeringIC 434 Panel 1L5s335.23—
23:29:40centeringIC 434 Panel 1L5s00.00—
23:29:49centeringIC 434 Panel 1L5s00.00—
23:29:59centeringIC 434 Panel 1L5s00.00—
23:31:20centeringIC 434 Panel 1L5s434.58—
23:31:29centeringIC 434 Panel 1L5s234.59—
23:31:39centeringIC 434 Panel 1L5s534.40—
23:31:55centeringIC 434 Panel 1L5s00.00—
23:32:05centeringIC 434 Panel 1L5s00.00—
23:32:14centeringIC 434 Panel 1L5s00.00—
23:33:35centeringIC 434 Panel 1L5s434.84—
23:33:44centeringIC 434 Panel 1L5s434.72—
23:33:54centeringIC 434 Panel 1L5s334.99—
23:34:10centeringIC 434 Panel 1L5s00.00—
23:34:20centeringIC 434 Panel 1L5s00.00—
23:34:30centeringIC 434 Panel 1L5s00.00—
00:23:39centeringIC 434 Panel 1L5s676.74—
00:24:04centeringIC 434 Panel 1L5s245.68—
00:24:37centeringIC 434 Panel 1L5s566.12—
00:25:03centeringIC 434 Panel 1L5s526.23—
00:26:56centeringIC 434 Panel 1L5s00.00—
00:27:08centeringIC 434 Panel 1L5s00.00—
00:27:19centeringIC 434 Panel 1L5s00.00—
00:27:46centeringIC 434 Panel 1L5s00.00—
00:28:00centeringIC 434 Panel 1L5s00.00—
00:28:14centeringIC 434 Panel 1L5s00.00—
02:35:28centeringIC 434 Panel 1L5s00.00—
02:35:43centeringIC 434 Panel 1L5s00.00—
02:35:58centeringIC 434 Panel 1L5s00.00—
02:36:13centeringIC 434 Panel 1L5s00.00—
02:36:28centeringIC 434 Panel 1L5s00.00—
02:36:58centeringIC 434 Panel 1L5s00.00—
02:37:18centeringIC 434 Panel 1L5s52.90—
02:37:38centeringIC 434 Panel 1L5s00.00—
02:37:58centeringIC 434 Panel 1L5s10.00—
02:38:18centeringIC 434 Panel 1L5s00.00—
03:21:37lightIC 434 Panel 1H300s10.0033%
03:29:19lightIC 434 Panel 1H300s10.0033%
03:37:23lightIC 434 Panel 1H300s49.38133%
03:44:55lightIC 434 Panel 1H300s311.05100%
03:52:29lightIC 434 Panel 1O300s59.63500%
03:59:33lightIC 434 Panel 1O300s00.000%
04:07:19lightIC 434 Panel 1O300s10.00100%
04:15:04lightIC 434 Panel 1O300s10.00100%
04:22:39lightIC 434 Panel 1S300s10.00100%
04:30:13lightIC 434 Panel 1S300s26.52200%
04:37:45lightIC 434 Panel 1S300s10.00100%
04:45:19lightIC 434 Panel 1S300s00.000%
04:46:03centeringIC 434 Panel 2L5s00.00—
04:46:18centeringIC 434 Panel 2L5s00.00—
04:46:33centeringIC 434 Panel 2L5s00.00—
04:46:48centeringIC 434 Panel 2L5s00.00—
04:47:03centeringIC 434 Panel 2L5s25.51—
04:47:23centeringIC 434 Panel 2L5s114.14—
04:47:43centeringIC 434 Panel 2L5s123.01—
04:48:03centeringIC 434 Panel 2L5s162.33—
04:48:23centeringIC 434 Panel 2L5s161.68—
04:48:43centeringIC 434 Panel 2L5s10.00—
04:49:13centeringIC 434 Panel 2L5s00.00—
04:49:33centeringIC 434 Panel 2L5s210.94—
04:49:53centeringIC 434 Panel 2L5s212.97—
04:50:13centeringIC 434 Panel 2L5s00.00—
04:50:33centeringIC 434 Panel 2L5s10.00—
04:50:53centeringIC 434 Panel 2L5s10.00—
05:04:30lightIC 434 Panel 2H300s156.73100%
05:05:24autofocusIC 434 Panel 2L5s163.60—
05:05:38autofocusIC 434 Panel 2L5s87.00—
05:05:53autofocusIC 434 Panel 2L5s126.30—
05:06:08autofocusIC 434 Panel 2L5s155.30—
05:06:23autofocusIC 434 Panel 2L5s224.36—
05:06:43autofocusIC 434 Panel 2L5s273.25—
05:07:03autofocusIC 434 Panel 2L5s362.61—
05:07:23autofocusIC 434 Panel 2L5s521.76—
05:07:43autofocusIC 434 Panel 2L5s531.43—
05:08:03autofocusIC 434 Panel 2L5s571.76—
05:08:23autofocusIC 434 Panel 2L5s402.45—
05:08:38autofocusIC 434 Panel 2L5s323.08—
05:08:53autofocusIC 434 Panel 2L5s204.30—
05:09:13autofocusIC 434 Panel 2L5s391.61—
05:15:09lightIC 434 Panel 2H300s392.27260%
05:22:31lightIC 434 Panel 2H300s82.5653%
05:30:03lightIC 434 Panel 2H300s54.0233%
05:37:37lightIC 434 Panel 2O300s00.000%
05:45:23lightIC 434 Panel 2O300s652.32100%
05:46:09autofocusIC 434 Panel 3L5s671.52—
05:46:23autofocusIC 434 Panel 3L5s363.93—
05:46:38autofocusIC 434 Panel 3L5s432.91—
05:46:53autofocusIC 434 Panel 3L5s572.24—
05:47:08autofocusIC 434 Panel 3L5s711.56—
05:47:28autofocusIC 434 Panel 3L5s661.47—
05:47:48autofocusIC 434 Panel 3L5s691.82—
05:48:08autofocusIC 434 Panel 3L5s532.70—
05:48:28autofocusIC 434 Panel 3L5s443.38—
05:48:48autofocusIC 434 Panel 3L5s314.46—
05:49:08autofocusIC 434 Panel 3L5s641.45—

Star counts come from Hocus Focus detection on each saved sub, tagged with the filter in place at exposure start and the target then being imaged. Frames inside completed autofocus runs are excluded. Still capture times come from the AllSky filenames. All times are local.