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: 12-17 (67), 12-16 (66), 12-15 (61), 12-14 (53), 12-13 (44) — by astronomy; check the weather when the night is within four days.

2044-11-18astronomy score per night — click a bar for that night2044-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-11-18 Fri	18	—	unknown	05:10–05:40 (good, 0.5 h)	50.1° 08:55	11.06	1%	44.2°
2044-11-19 Sat	19	—	unknown	05:05–05:40 (good, 0.58 h)	50.1° 08:55	11.09	0%	56.5°
2044-11-20 Sun	21	—	unknown	05:00–05:45 (good, 0.75 h)	50.1° 08:50	11.11	2%	68.7°
2044-11-21 Mon	22	—	unknown	05:00–05:45 (good, 0.75 h)	50.1° 08:45	11.14	5%	80.7°
2044-11-22 Tue	24	—	unknown	04:55–05:45 (good, 0.83 h)	50.1° 08:40	11.16	10%	92.5°
2044-11-23 Wed	26	—	unknown	04:50–05:45 (good, 0.92 h)	50.1° 08:35	11.18	16%	104.3°
2044-11-24 Thu	27	—	unknown	04:45–05:45 (good, 1.0 h)	50.1° 08:35	11.2	24%	116.0°
2044-11-25 Fri	29	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:30	11.23	32%	127.7°
2044-11-26 Sat	31	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:25	11.25	41%	139.4°
2044-11-27 Sun	33	—	unknown	04:35–05:50 (good, 1.25 h)	50.1° 08:20	11.27	51%	151.2°
2044-11-28 Mon	34	—	unknown	04:30–05:50 (good, 1.33 h)	50.1° 08:15	11.29	61%	162.9°
2044-11-29 Tue	35	—	unknown	04:25–05:50 (good, 1.42 h)	50.1° 08:15	11.31	70%	172.2°
2044-11-30 Wed	37	—	unknown	04:25–05:50 (good, 1.42 h)	50.1° 08:10	11.32	80%	167.5°
2044-12-01 Thu	39	—	unknown	04:20–05:55 (good, 1.58 h)	50.1° 08:05	11.34	88%	155.1°
2044-12-02 Fri	39	—	unknown	04:25–05:55 (good, 1.5 h)	50.1° 08:00	11.36	94%	141.5°
2044-12-03 Sat	35	—	unknown	04:20–05:55 (good, 1.58 h)	50.1° 08:00	11.37	98%	127.3°
2044-12-04 Sun	32	—	unknown	04:25–05:55 (good, 1.5 h)	50.1° 07:55	11.39	100%	112.7°
2044-12-05 Mon	25	—	unknown	04:50–05:55 (good, 1.08 h)	50.1° 07:50	11.4	98%	97.8°
2044-12-06 Tue	20	—	unknown	03:45–06:00 (marginal, 2.25 h)	50.1° 07:45	11.42	94%	82.9°
2044-12-07 Wed	16	—	unknown	03:50–06:00 (marginal, 2.17 h)	50.1° 07:40	11.43	88%	68.0°
2044-12-08 Thu	15	—	unknown	03:45–06:00 (marginal, 2.25 h)	50.1° 07:40	11.44	79%	53.5°
2044-12-09 Fri	15	—	unknown	03:40–06:00 (marginal, 2.33 h)	50.1° 07:35	11.45	68%	39.3°
2044-12-10 Sat	19	—	unknown	03:25–06:00 (marginal, 2.58 h)	50.1° 07:30	11.46	58%	25.6°
2044-12-11 Sun	27	—	unknown	05:25–06:00 (good, 0.58 h)	50.1° 07:25	11.47	47%	13.2°
2044-12-12 Mon	35	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:20	11.48	36%	7.7°
2044-12-13 Tue	44	—	unknown	03:45–06:05 (good, 2.33 h)	50.1° 07:20	11.48	26%	17.0°
2044-12-14 Wed	53	—	unknown	03:30–06:05 (good, 2.58 h)	50.1° 07:15	11.49	18%	29.0°
2044-12-15 Thu	61	—	unknown	03:25–06:05 (good, 2.67 h)	50.1° 07:10	11.49	11%	41.2°
2044-12-16 Fri	66	—	unknown	03:20–06:05 (good, 2.75 h)	50.1° 07:05	11.5	6%	53.4°
2044-12-17 Sat	67	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 07:05	11.5	2%	65.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-11-18&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.