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: 12-11 (56), 12-10 (55), 12-09 (53), 12-08 (51), 12-07 (49) — by astronomy; check the weather when the night is within four days.

2045-11-12astronomy score per night — click a bar for that night2045-12-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-11-12 Sun	7	—	unknown	05:05–06:05 (marginal, 1.0 h)	50.1° 09:20	10.88	17%	94.2°
2045-11-13 Mon	9	—	unknown	05:30–05:35 (good, 0.08 h)	50.1° 09:15	10.91	25%	106.4°
2045-11-14 Tue	10	—	unknown	05:25–05:35 (good, 0.17 h)	50.1° 09:15	10.94	34%	118.4°
2045-11-15 Wed	12	—	unknown	05:25–05:40 (good, 0.25 h)	50.1° 09:10	10.97	43%	130.1°
2045-11-16 Thu	14	—	unknown	05:20–05:40 (good, 0.33 h)	50.1° 09:05	11.0	53%	141.7°
2045-11-17 Fri	16	—	unknown	05:15–05:40 (good, 0.42 h)	50.1° 09:00	11.03	62%	153.0°
2045-11-18 Sat	17	—	unknown	05:10–05:40 (good, 0.5 h)	50.1° 09:00	11.05	71%	163.9°
2045-11-19 Sun	19	—	unknown	05:05–05:40 (good, 0.58 h)	50.1° 08:55	11.08	79%	171.3°
2045-11-20 Mon	21	—	unknown	05:05–05:45 (good, 0.67 h)	50.1° 08:50	11.1	86%	166.4°
2045-11-21 Tue	22	—	unknown	05:05–05:45 (good, 0.67 h)	50.1° 08:45	11.13	93%	155.3°
2045-11-22 Wed	20	—	unknown	05:05–05:45 (good, 0.67 h)	50.1° 08:40	11.15	97%	142.9°
2045-11-23 Thu	20	—	unknown	05:00–05:45 (good, 0.75 h)	50.1° 08:40	11.18	99%	130.0°
2045-11-24 Fri	20	—	unknown	05:00–05:45 (good, 0.75 h)	50.1° 08:35	11.2	100%	116.7°
2045-11-25 Sat	17	—	unknown	05:10–05:50 (good, 0.67 h)	50.1° 08:30	11.22	97%	103.1°
2045-11-26 Sun	14	—	unknown	04:20–05:50 (marginal, 1.5 h)	50.1° 08:25	11.24	93%	89.3°
2045-11-27 Mon	12	—	unknown	04:20–05:50 (marginal, 1.5 h)	50.1° 08:20	11.26	86%	75.4°
2045-11-28 Tue	11	—	unknown	04:20–05:50 (marginal, 1.5 h)	50.1° 08:20	11.28	77%	61.4°
2045-11-29 Wed	12	—	unknown	04:15–05:50 (marginal, 1.58 h)	50.1° 08:15	11.3	67%	47.4°
2045-11-30 Thu	14	—	unknown	04:05–05:50 (marginal, 1.75 h)	50.1° 08:10	11.32	56%	33.6°
2045-12-01 Fri	19	—	unknown	05:50–05:55 (good, 0.08 h)	50.1° 08:05	11.34	44%	20.4°
2045-12-02 Sat	25	—	unknown	04:35–05:55 (good, 1.33 h)	50.1° 08:05	11.35	33%	9.7°
2045-12-03 Sun	32	—	unknown	04:25–05:55 (good, 1.5 h)	50.1° 08:00	11.37	23%	12.8°
2045-12-04 Mon	38	—	unknown	04:10–05:55 (good, 1.75 h)	50.1° 07:55	11.39	14%	24.8°
2045-12-05 Tue	44	—	unknown	04:05–05:55 (good, 1.83 h)	50.1° 07:50	11.4	8%	37.8°
2045-12-06 Wed	47	—	unknown	04:00–05:55 (good, 1.92 h)	50.1° 07:45	11.41	3%	51.0°
2045-12-07 Thu	49	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:45	11.43	0%	64.1°
2045-12-08 Fri	51	—	unknown	03:50–06:00 (good, 2.17 h)	50.1° 07:40	11.44	0%	77.0°
2045-12-09 Sat	53	—	unknown	03:50–06:00 (good, 2.17 h)	50.1° 07:35	11.45	2%	89.7°
2045-12-10 Sun	55	—	unknown	03:45–06:00 (good, 2.25 h)	50.1° 07:30	11.46	6%	102.1°
2045-12-11 Mon	56	—	unknown	03:40–06:00 (good, 2.33 h)	50.1° 07:25	11.47	12%	114.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-11-12&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.