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: 06-03 (32), 06-16 (27), 06-17 (26), 06-04 (25), 06-15 (25) — by astronomy; check the weather when the night is within four days.

2033-06-03astronomy score per night — click a bar for that night2033-07-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-06-03 Fri	32	—	unknown	23:00–00:35 (good, 1.58 h)	50.2° 21:00	4.72	40%	34.9°
2033-06-04 Sat	25	—	unknown	23:00–00:20 (good, 1.33 h)	50.2° 21:00	4.68	50%	23.2°
2033-06-05 Sun	20	—	unknown	23:05–01:10 (marginal, 2.08 h)	50.2° 20:55	4.65	59%	12.1°
2033-06-06 Mon	15	—	unknown	23:05–01:00 (marginal, 1.92 h)	50.2° 20:50	4.63	68%	6.1°
2033-06-07 Tue	12	—	unknown	23:05–00:50 (marginal, 1.75 h)	50.2° 20:45	4.6	76%	14.4°
2033-06-08 Wed	9	—	unknown	23:05–00:35 (marginal, 1.5 h)	50.2° 20:40	4.57	84%	25.9°
2033-06-09 Thu	9	—	unknown	23:05–00:30 (marginal, 1.42 h)	50.2° 20:40	4.55	91%	37.8°
2033-06-10 Fri	10	—	unknown	23:05–00:30 (marginal, 1.42 h)	50.2° 20:35	4.53	96%	50.1°
2033-06-11 Sat	12	—	unknown	23:10–00:35 (marginal, 1.42 h)	50.2° 20:30	4.51	99%	62.7°
2033-06-12 Sun	15	—	unknown	23:10–00:40 (marginal, 1.5 h)	50.2° 20:25	4.49	100%	75.6°
2033-06-13 Mon	19	—	unknown	23:10–23:40 (good, 0.5 h)	50.2° 20:25	4.48	99%	88.7°
2033-06-14 Tue	22	—	unknown	23:10–23:50 (good, 0.67 h)	50.2° 20:20	4.46	95%	102.1°
2033-06-15 Wed	25	—	unknown	23:10–23:55 (good, 0.75 h)	50.2° 20:15	4.45	90%	115.7°
2033-06-16 Thu	27	—	unknown	23:10–23:55 (good, 0.75 h)	50.2° 20:10	4.44	82%	129.5°
2033-06-17 Fri	26	—	unknown	23:10–00:00 (good, 0.83 h)	50.2° 20:05	4.43	73%	143.3°
2033-06-18 Sat	25	—	unknown	23:10–23:55 (good, 0.75 h)	50.2° 20:05	4.43	62%	157.0°
2033-06-19 Sun	24	—	unknown	23:10–23:50 (good, 0.67 h)	50.2° 20:00	4.42	51%	170.0°
2033-06-20 Mon	22	—	unknown	23:15–23:45 (good, 0.5 h)	50.2° 19:55	4.42	39%	171.5°
2033-06-21 Tue	20	—	unknown	23:15–23:45 (good, 0.5 h)	50.2° 19:50	4.42	28%	158.9°
2033-06-22 Wed	18	—	unknown	23:15–23:40 (good, 0.42 h)	50.2° 19:45	4.43	19%	145.1°
2033-06-23 Thu	17	—	unknown	23:15–23:35 (good, 0.33 h)	50.2° 19:45	4.43	11%	131.1°
2033-06-24 Fri	15	—	unknown	23:15–23:30 (good, 0.25 h)	50.2° 19:40	4.44	5%	117.2°
2033-06-25 Sat	14	—	unknown	23:15–23:25 (good, 0.17 h)	50.2° 19:35	4.45	1%	103.5°
2033-06-26 Sun	12	—	unknown	23:15–23:25 (good, 0.17 h)	50.2° 19:30	4.46	0%	90.0°
2033-06-27 Mon	11	—	unknown	23:15–23:20 (good, 0.08 h)	50.2° 19:25	4.47	2%	76.8°
2033-06-28 Tue	11	—	unknown	23:10–23:15 (good, 0.08 h)	50.2° 19:25	4.49	5%	63.9°
2033-06-29 Wed	10	—	unknown	22:20–23:40 (marginal, 1.33 h)	50.2° 19:20	4.5	10%	51.3°
2033-06-30 Thu	8	—	unknown	22:20–23:00 (marginal, 0.67 h)	50.2° 19:15	4.52	17%	39.0°
2033-07-01 Fri	6	—	unknown	22:20–22:55 (marginal, 0.58 h)	50.2° 19:10	4.54	25%	27.0°
2033-07-02 Sat	5	—	unknown	23:10–23:30 (marginal, 0.33 h)	50.2° 19:10	4.57	33%	15.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-03&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.