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: 05-31 (54), 05-30 (53), 06-01 (52), 06-02 (51), 06-03 (49) — by astronomy; check the weather when the night is within four days.

2029-05-30astronomy score per night — click a bar for that night2029-06-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-05-30 Wed	53	—	unknown	22:55–00:55 (good, 2.0 h)	50.2° 21:15	4.86	88%	105.2°
2029-05-31 Thu	54	—	unknown	22:55–01:00 (good, 2.08 h)	50.2° 21:15	4.82	80%	118.3°
2029-06-01 Fri	52	—	unknown	23:00–00:55 (good, 1.92 h)	50.2° 21:10	4.79	70%	130.9°
2029-06-02 Sat	51	—	unknown	23:00–01:00 (good, 2.0 h)	50.2° 21:05	4.75	61%	143.0°
2029-06-03 Sun	49	—	unknown	23:00–00:55 (good, 1.92 h)	50.2° 21:00	4.72	51%	154.5°
2029-06-04 Mon	48	—	unknown	23:00–00:50 (good, 1.83 h)	50.2° 21:00	4.68	42%	164.7°
2029-06-05 Tue	45	—	unknown	23:05–00:45 (good, 1.67 h)	50.2° 20:55	4.65	32%	170.0°
2029-06-06 Wed	44	—	unknown	23:05–00:40 (good, 1.58 h)	50.2° 20:50	4.63	24%	164.3°
2029-06-07 Thu	42	—	unknown	23:05–00:40 (good, 1.58 h)	50.2° 20:45	4.6	16%	154.1°
2029-06-08 Fri	40	—	unknown	23:05–00:35 (good, 1.5 h)	50.2° 20:40	4.57	10%	142.9°
2029-06-09 Sat	39	—	unknown	23:05–00:30 (good, 1.42 h)	50.2° 20:40	4.55	5%	131.3°
2029-06-10 Sun	38	—	unknown	23:05–00:25 (good, 1.33 h)	50.2° 20:35	4.53	2%	119.3°
2029-06-11 Mon	35	—	unknown	23:10–00:20 (good, 1.17 h)	50.2° 20:30	4.51	0%	107.1°
2029-06-12 Tue	33	—	unknown	23:10–00:20 (good, 1.17 h)	50.2° 20:25	4.49	1%	94.6°
2029-06-13 Wed	33	—	unknown	23:10–00:15 (good, 1.08 h)	50.2° 20:20	4.48	3%	81.9°
2029-06-14 Thu	30	—	unknown	23:10–00:10 (good, 1.0 h)	50.2° 20:20	4.46	8%	69.0°
2029-06-15 Fri	28	—	unknown	23:10–00:05 (good, 0.92 h)	50.2° 20:15	4.45	15%	56.0°
2029-06-16 Sat	23	—	unknown	23:10–00:05 (good, 0.92 h)	50.2° 20:10	4.44	24%	42.8°
2029-06-17 Sun	19	—	unknown	23:10–23:45 (good, 0.58 h)	50.2° 20:05	4.43	34%	29.7°
2029-06-18 Mon	15	—	unknown	23:10–23:30 (good, 0.33 h)	50.2° 20:05	4.43	44%	17.3°
2029-06-19 Tue	12	—	unknown	23:10–00:20 (marginal, 1.17 h)	50.2° 20:00	4.42	56%	10.1°
2029-06-20 Wed	9	—	unknown	23:15–00:05 (marginal, 0.83 h)	50.2° 19:55	4.42	67%	17.3°
2029-06-21 Thu	6	—	unknown	23:15–23:55 (marginal, 0.67 h)	50.2° 19:50	4.42	78%	30.1°
2029-06-22 Fri	6	—	unknown	23:15–23:50 (marginal, 0.58 h)	50.2° 19:45	4.43	87%	44.0°
2029-06-23 Sat	6	—	unknown	23:15–23:50 (marginal, 0.58 h)	50.2° 19:45	4.43	94%	58.0°
2029-06-24 Sun	7	—	unknown	23:15–23:50 (marginal, 0.58 h)	50.2° 19:40	4.44	98%	72.1°
2029-06-25 Mon	8	—	unknown	23:15–23:55 (marginal, 0.67 h)	50.2° 19:35	4.45	100%	86.1°
2029-06-26 Tue	8	—	unknown	23:15–23:50 (marginal, 0.58 h)	50.2° 19:30	4.46	99%	99.8°
2029-06-27 Wed	9	—	unknown	22:20–23:10 (marginal, 0.83 h)	50.2° 19:25	4.47	96%	113.2°
2029-06-28 Thu	10	—	unknown	22:20–23:45 (marginal, 1.42 h)	50.2° 19:25	4.49	91%	126.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-05-30&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.