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: 03-15 (93), 03-16 (93), 03-17 (93), 03-18 (93), 03-19 (93) — by astronomy; check the weather when the night is within four days.

2048-03-15astronomy score per night — click a bar for that night2048-04-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-03-15 Sun	93	—	unknown	21:30–05:00 (good, 7.5 h)	50.1° 01:15	8.94	2%	168.7°
2048-03-16 Mon	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.1° 01:10	8.89	6%	159.4°
2048-03-17 Tue	93	—	unknown	21:20–04:55 (good, 7.58 h)	50.1° 01:10	8.84	11%	148.2°
2048-03-18 Wed	93	—	unknown	21:20–04:55 (good, 7.58 h)	50.1° 01:05	8.79	18%	136.6°
2048-03-19 Thu	93	—	unknown	21:15–04:50 (good, 7.58 h)	50.1° 01:00	8.74	25%	125.0°
2048-03-20 Fri	93	—	unknown	21:15–04:50 (good, 7.58 h)	50.1° 00:55	8.69	34%	113.4°
2048-03-21 Sat	93	—	unknown	21:15–04:45 (good, 7.5 h)	50.1° 00:50	8.64	43%	101.8°
2048-03-22 Sun	91	—	unknown	21:20–04:40 (good, 7.33 h)	50.1° 00:50	8.58	52%	90.0°
2048-03-23 Mon	87	—	unknown	21:35–04:35 (good, 7.0 h)	50.1° 00:45	8.53	62%	78.1°
2048-03-24 Tue	84	—	unknown	23:10–04:30 (good, 5.33 h)	50.1° 00:40	8.48	71%	65.9°
2048-03-25 Wed	80	—	unknown	02:15–04:30 (good, 2.25 h)	50.1° 00:35	8.42	80%	53.5°
2048-03-26 Thu	51	—	unknown	21:05–04:40 (marginal, 7.58 h)	50.1° 00:30	8.37	88%	40.7°
2048-03-27 Fri	31	—	unknown	23:05–04:35 (marginal, 5.5 h)	50.1° 00:30	8.32	94%	27.9°
2048-03-28 Sat	27	—	unknown	23:25–05:25 (marginal, 5.0 h)	50.1° 00:25	8.26	98%	15.7°
2048-03-29 Sun	25	—	unknown	21:45–05:10 (marginal, 7.42 h)	50.1° 01:20	8.21	100%	9.9°
2048-03-30 Mon	31	—	unknown	21:25–05:00 (marginal, 7.58 h)	50.1° 01:15	8.15	99%	19.0°
2048-03-31 Tue	74	—	unknown	21:25–22:00 (good, 0.58 h)	50.1° 01:15	8.1	95%	32.5°
2048-04-01 Wed	88	—	unknown	21:25–00:15 (good, 2.83 h)	50.1° 01:10	8.05	89%	46.6°
2048-04-02 Thu	93	—	unknown	21:25–03:15 (good, 5.83 h)	50.1° 01:05	7.99	80%	60.9°
2048-04-03 Fri	93	—	unknown	21:30–04:25 (good, 6.92 h)	50.1° 01:00	7.93	70%	75.2°
2048-04-04 Sat	93	—	unknown	21:30–04:35 (good, 7.08 h)	50.1° 00:55	7.88	59%	89.2°
2048-04-05 Sun	93	—	unknown	21:30–04:35 (good, 7.08 h)	50.1° 00:55	7.82	48%	103.0°
2048-04-06 Mon	93	—	unknown	21:30–04:35 (good, 7.08 h)	50.1° 00:50	7.77	37%	116.5°
2048-04-07 Tue	93	—	unknown	21:35–04:35 (good, 7.0 h)	50.1° 00:45	7.71	27%	129.6°
2048-04-08 Wed	93	—	unknown	21:35–04:35 (good, 7.0 h)	50.1° 00:40	7.65	18%	142.4°
2048-04-09 Thu	93	—	unknown	21:35–04:30 (good, 6.92 h)	50.1° 00:35	7.6	11%	154.7°
2048-04-10 Fri	93	—	unknown	21:40–04:25 (good, 6.75 h)	50.1° 00:35	7.54	5%	165.6°
2048-04-11 Sat	93	—	unknown	21:40–04:20 (good, 6.67 h)	50.1° 00:30	7.48	2%	170.0°
2048-04-12 Sun	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.1° 00:25	7.43	0%	162.7°
2048-04-13 Mon	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.1° 00:20	7.37	1%	151.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-03-15&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.