Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for 3C 273: 11-28 (33), 11-29 (33), 11-27 (31), 12-01 (30), 11-26 (29) — by astronomy; check the weather when the night is within four days.

2047-11-09astronomy score per night — click a bar for that night2047-12-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-11-09 Sat	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.1° 09:35	10.77	59%	59.4°
2047-11-10 Sun	2	—	unknown	05:20–05:30 (marginal, 0.17 h)	50.1° 09:30	10.81	49%	46.9°
2047-11-11 Mon	3	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.1° 09:25	10.84	38%	34.2°
2047-11-12 Tue	4	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.1° 09:25	10.87	28%	21.6°
2047-11-13 Wed	6	—	unknown	05:05–05:35 (marginal, 0.5 h)	50.1° 09:20	10.9	18%	11.2°
2047-11-14 Thu	8	—	unknown	05:00–06:10 (marginal, 1.17 h)	50.1° 09:15	10.93	10%	13.7°
2047-11-15 Fri	11	—	unknown	05:25–05:35 (good, 0.17 h)	50.1° 09:10	10.96	4%	26.2°
2047-11-16 Sat	13	—	unknown	05:20–05:40 (good, 0.33 h)	50.1° 09:10	10.98	1%	40.6°
2047-11-17 Sun	14	—	unknown	05:15–05:40 (good, 0.42 h)	50.1° 09:05	11.01	0%	55.5°
2047-11-18 Mon	16	—	unknown	05:15–05:40 (good, 0.42 h)	50.1° 09:00	11.04	3%	70.4°
2047-11-19 Tue	18	—	unknown	05:10–05:40 (good, 0.5 h)	50.1° 08:55	11.07	8%	85.2°
2047-11-20 Wed	20	—	unknown	05:05–05:40 (good, 0.58 h)	50.1° 08:50	11.09	16%	99.5°
2047-11-21 Thu	21	—	unknown	05:00–05:45 (good, 0.75 h)	50.1° 08:50	11.12	25%	113.4°
2047-11-22 Fri	23	—	unknown	04:55–05:45 (good, 0.83 h)	50.1° 08:45	11.14	35%	126.8°
2047-11-23 Sat	24	—	unknown	04:55–05:45 (good, 0.83 h)	50.1° 08:40	11.17	46%	139.5°
2047-11-24 Sun	26	—	unknown	04:50–05:45 (good, 0.92 h)	50.1° 08:35	11.19	56%	151.7°
2047-11-25 Mon	28	—	unknown	04:45–05:45 (good, 1.0 h)	50.1° 08:30	11.21	65%	162.7°
2047-11-26 Tue	29	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:30	11.23	74%	169.8°
2047-11-27 Wed	31	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:25	11.25	82%	165.9°
2047-11-28 Thu	33	—	unknown	04:35–05:50 (good, 1.25 h)	50.1° 08:20	11.27	89%	156.0°
2047-11-29 Fri	33	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:15	11.29	94%	145.0°
2047-11-30 Sat	29	—	unknown	04:35–05:50 (good, 1.25 h)	50.1° 08:10	11.31	98%	133.6°
2047-12-01 Sun	30	—	unknown	04:35–05:55 (good, 1.33 h)	50.1° 08:10	11.33	100%	122.0°
2047-12-02 Mon	27	—	unknown	04:40–05:55 (good, 1.25 h)	50.1° 08:05	11.35	100%	110.3°
2047-12-03 Tue	24	—	unknown	04:55–05:55 (good, 1.0 h)	50.1° 08:00	11.36	98%	98.5°
2047-12-04 Wed	20	—	unknown	05:50–05:55 (good, 0.08 h)	50.1° 07:55	11.38	95%	86.6°
2047-12-05 Thu	17	—	unknown	03:55–05:55 (marginal, 2.0 h)	50.1° 07:55	11.39	90%	74.6°
2047-12-06 Fri	15	—	unknown	03:55–05:55 (marginal, 2.0 h)	50.1° 07:50	11.41	83%	62.4°
2047-12-07 Sat	15	—	unknown	03:50–06:00 (marginal, 2.17 h)	50.1° 07:45	11.42	74%	50.1°
2047-12-08 Sun	16	—	unknown	03:45–06:00 (marginal, 2.25 h)	50.1° 07:40	11.43	65%	37.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-11-09&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.