Sky transparency — night of 10–11 October 2026

Cloud arrived at 21:11 — detected by the all-sky camera, independent of N.I.N.A. Before it the sky ran at index 100 (IQR 87–102); after it 14 (IQR 1–70). 5 of 31 light frames landed before the cloud. 131 of 131 failures are attributed to cloud. Guiding ran at 0.95″ RMS before the cloud and 4.42″ after; the worst minute was 27.39″ at 03:51. The 02:49 autofocus run fitted its curve on almost no stars and should not be trusted. The 03:52 autofocus run fitted its curve on almost no stars and should not be trusted. Morning sky flats: 63 frames (O 21, S 21, H 21), 06:44–06:49, auto-exposure 0.2–0.6 s.

Index before 21:11

100 · IQR 87–102

Index after 21:11

14 · IQR 1–70

Cloud onset (all-sky)

21:11 · independent

Errors after onset

131 of 131 · solve + PHD2

Guide RMS

3.80″ · RA 2.79 · Dec 2.57

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

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.

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. 1168 guide frames over 3.6 h of guiding in 22 sessions; the gaps are slews, dither settles and autofocus runs, when PHD2 was not guiding. PHD2 discarded 986 further frames — usually a lost star. The worst minute (27.39″ at 03:51) is clamped at the top of the plot.

RA RMS Dec RMS ◆ PHD2 error

All‑sky frames at the key moments

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

All-sky at 20:34 — **20:34** · start of night

All-sky at 21:11 — **21:11** · cloud onset

All-sky at 05:44 — **05:44** · peak brightness 116.7

All-sky at 06:14 — **06:14** · end of night

Clear‑sky reference medians

The divisors behind the index — median detected stars per light sub before 21:11.

Target	Filter	Median stars	Frames	Source
IC 434 Panel 1	H	178	4	earlier clear nights
IC 434 Panel 1	O	132	4	earlier clear nights
IC 434 Panel 1	S	269	4	earlier clear nights
IC 434 Panel 2	H	220	4	earlier clear nights
IC 434 Panel 2	O	196	4	earlier clear nights
M 17	H	842	4	tonight, clear frames
M 17	O	601	1	tonight, clear frames
M 17	S	1804	14	earlier clear nights

Event timeline

All observatory events with their attributed causes.

21:14:20PHD2timed-out waiting for guider to settlecloud

21:21:25PHD2timed-out waiting for guider to settlecloud

21:24:32PHD2timed-out waiting for guider to settlecloud

21:49:25PHD2timed-out waiting for guider to settlecloud

21:54:48PHD2failed to find a suitable guide starcloud

21:55:59PHD2failed to find a suitable guide starcloud

22:02:27PHD2timed-out waiting for guider to settlecloud

22:07:31solve failedASTAP plate solve failedcloud

22:07:49solve failedASTAP plate solve failedcloud

22:09:43PHD2timed-out waiting for guider to settlecloud

22:13:27AF failedautofocus run started 22:09:43 did not completecloud

22:14:49PHD2failed to find a suitable guide starcloud

22:19:51solve failedASTAP plate solve failedcloud

22:19:58solve failedASTAP plate solve failedcloud

22:23:52AF failedautofocus run started 22:19:49 did not completecloud

22:24:23PHD2failed to find a suitable guide starcloud

22:26:02PHD2failed to find a suitable guide starcloud

22:33:26PHD2timed-out waiting for guider to settlecloud

22:38:29solve failedASTAP plate solve failedcloud

22:38:41solve failedASTAP plate solve failedcloud

22:41:52AF failedautofocus run started 22:38:27 did not completecloud

22:43:17PHD2Guiding stoppedcloud

02:31:39solve failedASTAP plate solve failedcloud

02:32:23solve failedASTAP plate solve failedcloud

03:18:32PHD2timed-out waiting for guider to settlecloud

03:25:55PHD2timed-out waiting for guider to settlecloud

03:30:59solve failedASTAP plate solve failedcloud

03:31:10solve failedASTAP plate solve failedcloud

03:33:02PHD2timed-out waiting for guider to settlecloud

03:41:38AF failedautofocus run started 03:33:03 did not completecloud

03:44:45PHD2timed-out waiting for guider to settlecloud

03:46:50PHD2timed-out waiting for guider to settlecloud

03:56:08solve failedASTAP plate solve failedcloud

03:56:13solve failedASTAP plate solve failedcloud

03:58:18solve failedASTAP plate solve failedcloud

03:58:19solve failedASTAP plate solve failedcloud

04:00:24solve failedASTAP plate solve failedcloud

04:00:25solve failedASTAP plate solve failedcloud

04:06:30PHD2timed-out waiting for guider to settlecloud

04:10:06PHD2timed-out waiting for guider to settlecloud

04:17:20PHD2timed-out waiting for guider to settlecloud

04:22:22solve failedASTAP plate solve failedcloud

04:22:34solve failedASTAP plate solve failedcloud

04:31:45PHD2timed-out waiting for guider to settlecloud

04:39:06PHD2timed-out waiting for guider to settlecloud

04:39:38solve failedASTAP plate solve failedcloud

04:39:39solve failedASTAP plate solve failedcloud

04:41:44solve failedASTAP plate solve failedcloud

04:43:50solve failedASTAP plate solve failedcloud

04:43:56solve failedASTAP plate solve failedcloud

04:46:02solve failedASTAP plate solve failedcloud

04:48:08solve failedASTAP plate solve failedcloud

04:50:13solve failedASTAP plate solve failedcloud

04:50:14solve failedASTAP plate solve failedcloud

04:52:19solve failedASTAP plate solve failedcloud

04:52:20solve failedASTAP plate solve failedcloud

04:54:25solve failedASTAP plate solve failedcloud

04:54:30solve failedASTAP plate solve failedcloud

04:56:35solve failedASTAP plate solve failedcloud

04:56:36solve failedASTAP plate solve failedcloud

04:58:41solve failedASTAP plate solve failedcloud

04:58:42solve failedASTAP plate solve failedcloud

05:01:30PHD2timed-out waiting for guider to settlecloud

05:04:05PHD2timed-out waiting for guider to settlecloud

05:09:08solve failedASTAP plate solve failedcloud

05:09:19solve failedASTAP plate solve failedcloud

05:11:07PHD2timed-out waiting for guider to settlecloud

05:11:38solve failedASTAP plate solve failedcloud

05:11:39solve failedASTAP plate solve failedcloud

05:13:44solve failedASTAP plate solve failedcloud

05:13:45solve failedASTAP plate solve failedcloud

05:15:50solve failedASTAP plate solve failedcloud

05:15:51solve failedASTAP plate solve failedcloud

05:17:56solve failedASTAP plate solve failedcloud

05:17:57solve failedASTAP plate solve failedcloud

05:20:02solve failedASTAP plate solve failedcloud

05:20:03solve failedASTAP plate solve failedcloud

05:22:08solve failedASTAP plate solve failedcloud

05:22:09solve failedASTAP plate solve failedcloud

05:24:14solve failedASTAP plate solve failedcloud

05:26:20solve failedASTAP plate solve failedcloud

05:28:26solve failedASTAP plate solve failedcloud

05:28:27solve failedASTAP plate solve failedcloud

05:30:32solve failedASTAP plate solve failedcloud

05:35:23PHD2timed-out waiting for guider to settlecloud

05:44:03AF failedautofocus run started 05:40:08 did not completecloud

05:49:08AF failedautofocus run started 05:45:58 did not completecloud

05:49:43solve failedASTAP plate solve failedcloud

05:49:44solve failedASTAP plate solve failedcloud

05:51:49solve failedASTAP plate solve failedcloud

05:51:50solve failedASTAP plate solve failedcloud

05:53:55solve failedASTAP plate solve failedcloud

05:56:01solve failedASTAP plate solve failedcloud

05:58:07solve failedASTAP plate solve failedcloud

06:00:13solve failedASTAP plate solve failedcloud

06:02:18solve failedASTAP plate solve failedcloud

06:02:19solve failedASTAP plate solve failedcloud

06:04:24solve failedASTAP plate solve failedcloud

06:04:25solve failedASTAP plate solve failedcloud

06:06:30solve failedASTAP plate solve failedcloud

06:06:31solve failedASTAP plate solve failedcloud

06:08:36solve failedASTAP plate solve failedcloud

06:08:41solve failedASTAP plate solve failedcloud

06:09:37PHD2failed to find a suitable guide starcloud

06:14:28PHD2failed to find a suitable guide starcloud

06:15:02PHD2failed to find a suitable guide starcloud

06:16:23solve failedASTAP plate solve failedcloud

06:16:24solve failedASTAP plate solve failedcloud

06:18:29solve failedASTAP plate solve failedcloud

06:18:30solve failedASTAP plate solve failedcloud

06:20:35solve failedASTAP plate solve failedcloud

06:20:36solve failedASTAP plate solve failedcloud

06:22:41solve failedASTAP plate solve failedcloud

06:22:42solve failedASTAP plate solve failedcloud

06:24:47solve failedASTAP plate solve failedcloud

06:24:48solve failedASTAP plate solve failedcloud

06:26:53solve failedASTAP plate solve failedcloud

06:26:54solve failedASTAP plate solve failedcloud

06:28:59solve failedASTAP plate solve failedcloud

06:29:00solve failedASTAP plate solve failedcloud

06:31:05solve failedASTAP plate solve failedcloud

06:31:06solve failedASTAP plate solve failedcloud

06:33:11solve failedASTAP plate solve failedcloud

06:35:17solve failedASTAP plate solve failedcloud

06:37:59PHD2timed-out waiting for guider to settlecloud

All 151 frames (excludes the 63 sky flats — no stars to detect)

Time	Class	Target	Filter	Exp	Stars	HFR	Index
20:34:06	autofocus	M 17	L	5s	943	1.78	—
20:34:24	autofocus	M 17	L	5s	293	4.52	—
20:34:39	autofocus	M 17	L	5s	401	3.51	—
20:34:59	autofocus	M 17	L	5s	577	2.61	—
20:35:14	autofocus	M 17	L	5s	758	2.13	—
20:35:34	autofocus	M 17	L	5s	974	1.72	—
20:35:54	autofocus	M 17	L	5s	845	2.11	—
20:36:14	autofocus	M 17	L	5s	624	2.62	—
20:36:34	autofocus	M 17	L	5s	312	3.93	—
20:36:49	autofocus	M 17	L	5s	198	5.15	—
20:37:09	autofocus	M 17	L	5s	1052	1.64	—
20:43:31	light	M 17	H	300s	877	2.35	104%
20:49:01	light	M 17	H	300s	842	2.42	100%
20:54:57	light	M 17	H	300s	798	2.51	95%
21:00:23	light	M 17	H	300s	672	2.81	80%
21:06:05	light	M 17	O	300s	601	2.92	100%
21:11:50	light	M 17	O	300s	207	2.72	34%
21:19:22	light	M 17	O	300s	59	2.91	10%
21:33:34	light	M 17	O	300s	151	2.77	25%
21:40:10	light	M 17	S	300s	1	0.00	0%
21:47:00	light	M 17	S	300s	102	3.07	6%
21:54:28	light	M 17	S	300s	75	3.36	4%
22:07:29	light	M 17	S	300s	1	0.00	0%
22:10:09	centering	M 17	L	5s	0	0.00	—
22:10:29	centering	M 17	L	5s	0	0.00	—
22:10:44	centering	M 17	L	5s	0	0.00	—
22:10:59	centering	M 17	L	5s	0	0.00	—
22:11:13	centering	M 17	L	5s	0	0.00	—
22:11:44	centering	M 17	L	5s	0	0.00	—
22:12:04	centering	M 17	L	5s	4	1.92	—
22:12:24	centering	M 17	L	5s	1	0.00	—
22:12:44	centering	M 17	L	5s	1	0.00	—
22:13:04	centering	M 17	L	5s	1	0.00	—
22:19:50	light	M 17	H	300s	0	0.00	0%
22:20:09	centering	M 17	L	5s	1	0.00	—
22:20:28	centering	M 17	L	5s	0	0.00	—
22:20:44	centering	M 17	L	5s	0	0.00	—
22:21:04	centering	M 17	L	5s	4	4.69	—
22:21:19	centering	M 17	L	5s	3	3.85	—
22:21:39	centering	M 17	L	5s	0	0.00	—
22:21:59	centering	M 17	L	5s	0	0.00	—
22:22:29	centering	M 17	L	5s	0	0.00	—
22:22:49	centering	M 17	L	5s	0	0.00	—
22:23:09	centering	M 17	L	5s	0	0.00	—
22:23:29	centering	M 17	L	5s	0	0.00	—
22:38:29	light	M 17	H	300s	3	5.67	0%
22:38:49	centering	M 17	L	5s	0	0.00	—
22:39:09	centering	M 17	L	5s	0	0.00	—
22:39:24	centering	M 17	L	5s	0	0.00	—
22:39:43	centering	M 17	L	5s	0	0.00	—
22:39:59	centering	M 17	L	5s	0	0.00	—
22:40:29	centering	M 17	L	5s	0	0.00	—
22:40:49	centering	M 17	L	5s	0	0.00	—
22:41:09	centering	M 17	L	5s	0	0.00	—
22:41:29	centering	M 17	L	5s	0	0.00	—
02:15:29	autofocus	IC 434 Panel 1	L	5s	69	2.74	—
02:15:44	autofocus	IC 434 Panel 1	L	5s	32	7.01	—
02:15:59	autofocus	IC 434 Panel 1	L	5s	35	5.64	—
02:16:14	autofocus	IC 434 Panel 1	L	5s	71	4.58	—
02:16:29	autofocus	IC 434 Panel 1	L	5s	68	3.50	—
02:16:49	autofocus	IC 434 Panel 1	L	5s	99	2.34	—
02:17:09	autofocus	IC 434 Panel 1	L	5s	141	1.84	—
02:17:29	autofocus	IC 434 Panel 1	L	5s	42	1.93	—
02:17:49	autofocus	IC 434 Panel 1	L	5s	30	2.47	—
02:18:09	autofocus	IC 434 Panel 1	L	5s	27	3.26	—
02:18:24	autofocus	IC 434 Panel 1	L	5s	20	4.65	—
02:18:44	autofocus	IC 434 Panel 1	L	5s	38	1.87	—
02:26:02	light	IC 434 Panel 1	H	300s	67	2.73	38%
02:31:35	light	IC 434 Panel 1	H	300s	175	2.79	98%
02:37:05	light	IC 434 Panel 1	H	300s	162	2.75	91%
02:42:38	light	IC 434 Panel 1	H	300s	168	2.89	94%
02:48:48	light	IC 434 Panel 1	O	300s	141	3.09	107%
02:49:44	autofocus	IC 434 Panel 1	L	5s	69	1.73	—
02:50:04	autofocus	IC 434 Panel 1	L	5s	17	5.03	—
02:50:19	autofocus	IC 434 Panel 1	L	5s	17	4.16	—
02:50:34	autofocus	IC 434 Panel 1	L	5s	29	2.92	—
02:50:49	autofocus	IC 434 Panel 1	L	5s	36	2.19	—
02:51:09	autofocus	IC 434 Panel 1	L	5s	29	1.66	—
02:51:29	autofocus	IC 434 Panel 1	L	5s	22	1.87	—
02:51:49	autofocus	IC 434 Panel 1	L	5s	33	2.48	—
02:52:04	autofocus	IC 434 Panel 1	L	5s	17	3.73	—
02:52:19	autofocus	IC 434 Panel 1	L	5s	13	4.84	—
02:52:39	autofocus	IC 434 Panel 1	L	5s	65	1.62	—
02:58:47	light	IC 434 Panel 1	O	300s	148	3.52	112%
03:04:17	light	IC 434 Panel 1	O	300s	77	3.18	58%
03:10:04	light	IC 434 Panel 1	O	300s	127	3.38	96%
03:15:59	light	IC 434 Panel 1	S	300s	169	3.01	63%
03:23:35	light	IC 434 Panel 1	S	300s	44	3.55	16%
03:30:58	light	IC 434 Panel 1	S	300s	2	6.49	1%
03:33:24	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:33:39	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:33:54	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:34:09	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:34:24	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:34:54	centering	IC 434 Panel 1	L	5s	65	1.72	—
03:35:14	centering	IC 434 Panel 1	L	5s	96	2.14	—
03:35:34	centering	IC 434 Panel 1	L	5s	85	3.02	—
03:35:54	centering	IC 434 Panel 1	L	5s	4	4.01	—
03:36:14	centering	IC 434 Panel 1	L	5s	5	5.22	—
03:36:34	centering	IC 434 Panel 1	L	5s	2	6.63	—
03:36:54	centering	IC 434 Panel 1	L	5s	5	8.02	—
03:37:14	centering	IC 434 Panel 1	L	5s	5	8.94	—
03:37:34	centering	IC 434 Panel 1	L	5s	5	10.13	—
03:37:54	centering	IC 434 Panel 1	L	5s	6	11.48	—
03:38:14	centering	IC 434 Panel 1	L	5s	11	12.70	—
03:38:34	centering	IC 434 Panel 1	L	5s	4	13.95	—
03:38:54	centering	IC 434 Panel 1	L	5s	5	15.45	—
03:39:14	centering	IC 434 Panel 1	L	5s	4	16.65	—
03:39:34	centering	IC 434 Panel 1	L	5s	3	17.72	—
03:39:54	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:40:14	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:40:34	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:40:54	centering	IC 434 Panel 1	L	5s	3	23.07	—
03:41:14	centering	IC 434 Panel 1	L	5s	1	0.00	—
03:51:53	light	IC 434 Panel 1	S	300s	32	3.36	12%
03:52:34	autofocus	IC 434 Panel 2	L	5s	8	1.78	—
03:52:49	autofocus	IC 434 Panel 2	L	5s	3	4.70	—
03:53:04	autofocus	IC 434 Panel 2	L	5s	5	3.81	—
03:53:19	autofocus	IC 434 Panel 2	L	5s	7	2.69	—
03:53:34	autofocus	IC 434 Panel 2	L	5s	34	2.04	—
03:53:54	autofocus	IC 434 Panel 2	L	5s	33	1.61	—
03:54:14	autofocus	IC 434 Panel 2	L	5s	148	2.08	—
03:54:34	autofocus	IC 434 Panel 2	L	5s	4	3.24	—
03:54:54	autofocus	IC 434 Panel 2	L	5s	1	0.00	—
03:55:09	autofocus	IC 434 Panel 2	L	5s	1	0.00	—
03:55:29	autofocus	IC 434 Panel 2	L	5s	24	1.70	—
04:15:09	light	IC 434 Panel 2	H	300s	0	0.00	0%
04:22:21	light	IC 434 Panel 2	H	300s	17	3.98	8%
04:28:45	light	IC 434 Panel 2	H	300s	44	3.66	20%
04:36:48	light	IC 434 Panel 2	H	300s	9	4.33	4%
05:09:07	light	IC 434 Panel 2	O	300s	0	0.00	0%
05:40:24	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:40:44	centering	IC 434 Panel 3	L	5s	1	0.00	—
05:40:59	centering	IC 434 Panel 3	L	5s	2	3.34	—
05:41:14	centering	IC 434 Panel 3	L	5s	3	2.24	—
05:41:29	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:41:49	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:42:09	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:42:39	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:42:59	centering	IC 434 Panel 3	L	5s	1	0.00	—
05:43:19	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:43:39	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:46:14	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:46:29	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:46:44	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:46:59	centering	IC 434 Panel 3	L	5s	1	0.00	—
05:47:14	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:47:44	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:48:04	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:48:24	centering	IC 434 Panel 3	L	5s	0	0.00	—
05:48:44	centering	IC 434 Panel 3	L	5s	0	0.00	—

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.