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: 12-27 (84), 12-26 (83), 12-25 (82), 12-24 (79), 12-23 (78) — by astronomy; check the weather when the night is within four days.

2041-11-28astronomy score per night — click a bar for that night2041-12-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-11-28 Thu	33	—	unknown	04:30–05:50 (good, 1.33 h)	50.1° 08:20	11.28	29%	126.5°
2041-11-29 Fri	35	—	unknown	04:30–05:50 (good, 1.33 h)	50.1° 08:15	11.3	40%	140.5°
2041-11-30 Sat	36	—	unknown	04:25–05:50 (good, 1.42 h)	50.1° 08:10	11.32	51%	154.6°
2041-12-01 Sun	39	—	unknown	04:20–05:55 (good, 1.58 h)	50.1° 08:05	11.34	62%	168.6°
2041-12-02 Mon	40	—	unknown	04:15–05:55 (good, 1.67 h)	50.1° 08:05	11.35	73%	176.3°
2041-12-03 Tue	42	—	unknown	04:10–05:55 (good, 1.75 h)	50.1° 08:00	11.37	83%	162.6°
2041-12-04 Wed	43	—	unknown	04:15–05:55 (good, 1.67 h)	50.1° 07:55	11.38	90%	148.5°
2041-12-05 Thu	39	—	unknown	04:15–05:55 (good, 1.67 h)	50.1° 07:50	11.4	96%	134.5°
2041-12-06 Fri	38	—	unknown	04:10–05:55 (good, 1.75 h)	50.1° 07:45	11.41	99%	120.6°
2041-12-07 Sat	33	—	unknown	04:20–06:00 (good, 1.67 h)	50.1° 07:45	11.42	100%	107.0°
2041-12-08 Sun	27	—	unknown	05:05–06:00 (good, 0.92 h)	50.1° 07:40	11.44	98%	93.6°
2041-12-09 Mon	21	—	unknown	03:35–06:00 (marginal, 2.42 h)	50.1° 07:35	11.45	94%	80.5°
2041-12-10 Tue	18	—	unknown	03:40–06:00 (marginal, 2.33 h)	50.1° 07:30	11.46	89%	67.8°
2041-12-11 Wed	15	—	unknown	03:40–06:00 (marginal, 2.33 h)	50.1° 07:25	11.47	82%	55.4°
2041-12-12 Thu	15	—	unknown	03:35–06:00 (marginal, 2.42 h)	50.1° 07:25	11.47	74%	43.2°
2041-12-13 Fri	16	—	unknown	03:25–06:05 (marginal, 2.67 h)	50.1° 07:20	11.48	65%	31.2°
2041-12-14 Sat	22	—	unknown	03:10–06:05 (marginal, 2.92 h)	50.1° 07:15	11.49	56%	19.4°
2041-12-15 Sun	30	—	unknown	05:15–06:05 (good, 0.83 h)	50.1° 07:10	11.49	47%	7.8°
2041-12-16 Mon	38	—	unknown	03:45–06:05 (good, 2.33 h)	50.1° 07:05	11.5	37%	5.0°
2041-12-17 Tue	47	—	unknown	03:30–06:05 (good, 2.58 h)	50.1° 07:05	11.5	28%	16.6°
2041-12-18 Wed	56	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 07:00	11.5	20%	28.8°
2041-12-19 Thu	65	—	unknown	03:10–06:05 (good, 2.92 h)	50.1° 06:55	11.51	13%	41.3°
2041-12-20 Fri	72	—	unknown	03:05–06:05 (good, 3.0 h)	50.1° 06:50	11.51	7%	54.1°
2041-12-21 Sat	73	—	unknown	03:00–06:05 (good, 3.08 h)	50.1° 06:50	11.51	2%	67.3°
2041-12-22 Sun	76	—	unknown	02:55–06:10 (good, 3.25 h)	50.1° 06:45	11.51	0%	80.8°
2041-12-23 Mon	78	—	unknown	02:55–06:10 (good, 3.25 h)	50.1° 06:40	11.51	1%	94.6°
2041-12-24 Tue	79	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:35	11.5	3%	108.7°
2041-12-25 Wed	82	—	unknown	02:45–06:10 (good, 3.42 h)	50.1° 06:30	11.5	9%	122.9°
2041-12-26 Thu	83	—	unknown	02:40–06:10 (good, 3.5 h)	50.1° 06:30	11.49	16%	137.2°
2041-12-27 Fri	84	—	unknown	02:40–06:10 (good, 3.5 h)	50.1° 06:25	11.49	26%	151.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-11-28&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.