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: 12-26 (81), 12-27 (81), 12-25 (80), 12-28 (79), 12-24 (78) — by astronomy; check the weather when the night is within four days.

2047-12-03astronomy score per night — click a bar for that night2048-01-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2047-12-09 Mon	20	—	unknown	03:30–06:00 (marginal, 2.5 h)	50.1° 07:35	11.44	55%	25.3°
2047-12-10 Tue	27	—	unknown	04:40–06:00 (good, 1.33 h)	50.1° 07:35	11.45	44%	14.0°
2047-12-11 Wed	36	—	unknown	04:00–06:00 (good, 2.0 h)	50.1° 07:30	11.46	33%	10.8°
2047-12-12 Thu	45	—	unknown	03:50–06:00 (good, 2.17 h)	50.1° 07:25	11.47	22%	20.8°
2047-12-13 Fri	53	—	unknown	03:35–06:00 (good, 2.42 h)	50.1° 07:20	11.48	14%	34.3°
2047-12-14 Sat	60	—	unknown	03:30–06:05 (good, 2.58 h)	50.1° 07:15	11.48	6%	48.7°
2047-12-15 Sun	62	—	unknown	03:25–06:05 (good, 2.67 h)	50.1° 07:15	11.49	2%	63.5°
2047-12-16 Mon	65	—	unknown	03:25–06:05 (good, 2.67 h)	50.1° 07:10	11.5	0%	78.3°
2047-12-17 Tue	67	—	unknown	03:20–06:05 (good, 2.75 h)	50.1° 07:05	11.5	1%	93.1°
2047-12-18 Wed	68	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 07:00	11.5	5%	107.5°
2047-12-19 Thu	69	—	unknown	03:10–06:05 (good, 2.92 h)	50.1° 07:00	11.51	12%	121.5°
2047-12-20 Fri	71	—	unknown	03:05–06:05 (good, 3.0 h)	50.1° 06:55	11.51	20%	134.9°
2047-12-21 Sat	73	—	unknown	03:05–06:05 (good, 3.0 h)	50.1° 06:50	11.51	29%	147.7°
2047-12-22 Sun	74	—	unknown	03:00–06:05 (good, 3.08 h)	50.1° 06:45	11.51	39%	159.5°
2047-12-23 Mon	77	—	unknown	02:55–06:10 (good, 3.25 h)	50.1° 06:40	11.51	48%	168.5°
2047-12-24 Tue	78	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:40	11.5	58%	167.9°
2047-12-25 Wed	80	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:35	11.5	68%	158.9°
2047-12-26 Thu	81	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:30	11.5	76%	148.0°
2047-12-27 Fri	81	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:25	11.49	84%	136.7°
2047-12-28 Sat	79	—	unknown	02:45–06:10 (good, 3.42 h)	50.1° 06:20	11.49	90%	125.1°
2047-12-29 Sun	69	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:20	11.48	95%	113.5°
2047-12-30 Mon	59	—	unknown	02:55–06:10 (good, 3.25 h)	50.1° 06:15	11.47	98%	101.7°
2047-12-31 Tue	48	—	unknown	04:00–06:10 (good, 2.17 h)	50.1° 06:10	11.46	100%	89.7°
2048-01-01 Wed	38	—	unknown	05:25–06:10 (good, 0.75 h)	50.1° 06:05	11.45	100%	77.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-12-03&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.