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: 02-08 (93), 02-09 (93), 02-10 (93), 02-11 (93), 02-12 (93) — by astronomy; check the weather when the night is within four days.

2048-02-02astronomy score per night — click a bar for that night2048-03-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-02-02 Sun	23	—	unknown	00:30–06:00 (marginal, 5.5 h)	50.1° 04:00	10.74	90%	18.9°
2048-02-03 Mon	30	—	unknown	00:05–06:00 (marginal, 5.92 h)	50.1° 03:55	10.7	83%	10.2°
2048-02-04 Tue	41	—	unknown	23:45–05:55 (marginal, 6.17 h)	50.1° 03:55	10.67	74%	15.0°
2048-02-05 Wed	65	—	unknown	00:00–00:15 (good, 0.25 h)	50.1° 03:50	10.63	63%	27.0°
2048-02-06 Thu	86	—	unknown	00:00–05:55 (good, 5.92 h)	50.1° 03:45	10.6	52%	40.3°
2048-02-07 Fri	92	—	unknown	23:55–05:55 (good, 6.0 h)	50.1° 03:40	10.56	41%	54.0°
2048-02-08 Sat	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.1° 03:35	10.53	30%	67.9°
2048-02-09 Sun	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.1° 03:35	10.49	20%	81.9°
2048-02-10 Mon	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.1° 03:30	10.45	12%	96.0°
2048-02-11 Tue	93	—	unknown	23:40–05:50 (good, 6.17 h)	50.1° 03:25	10.41	5%	109.9°
2048-02-12 Wed	93	—	unknown	23:35–05:50 (good, 6.25 h)	50.1° 03:20	10.38	2%	123.7°
2048-02-13 Thu	93	—	unknown	23:30–05:50 (good, 6.33 h)	50.1° 03:20	10.34	0%	137.1°
2048-02-14 Fri	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.1° 03:15	10.3	1%	150.1°
2048-02-15 Sat	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.1° 03:10	10.26	4%	162.0°
2048-02-16 Sun	93	—	unknown	23:20–05:45 (good, 6.42 h)	50.1° 03:05	10.22	10%	169.9°
2048-02-17 Mon	93	—	unknown	23:15–05:45 (good, 6.5 h)	50.1° 03:00	10.18	16%	165.8°
2048-02-18 Tue	93	—	unknown	23:10–05:40 (good, 6.5 h)	50.1° 03:00	10.14	24%	155.4°
2048-02-19 Wed	93	—	unknown	23:10–05:40 (good, 6.5 h)	50.1° 02:55	10.1	33%	144.1°
2048-02-20 Thu	93	—	unknown	23:05–05:40 (good, 6.58 h)	50.1° 02:50	10.05	42%	132.6°
2048-02-21 Fri	93	—	unknown	23:05–05:35 (good, 6.5 h)	50.1° 02:45	10.01	51%	121.1°
2048-02-22 Sat	93	—	unknown	23:05–05:35 (good, 6.5 h)	50.1° 02:40	9.97	61%	109.4°
2048-02-23 Sun	92	—	unknown	23:10–05:35 (good, 6.42 h)	50.1° 02:40	9.93	70%	97.7°
2048-02-24 Mon	89	—	unknown	23:45–05:35 (good, 5.83 h)	50.1° 02:35	9.88	78%	85.7°
2048-02-25 Tue	86	—	unknown	01:20–05:30 (good, 4.17 h)	50.1° 02:30	9.84	86%	73.5°
2048-02-26 Wed	81	—	unknown	04:10–05:30 (good, 1.33 h)	50.1° 02:25	9.8	92%	61.1°
2048-02-27 Thu	42	—	unknown	23:00–05:30 (marginal, 6.5 h)	50.1° 02:25	9.75	97%	48.3°
2048-02-28 Fri	28	—	unknown	01:10–05:25 (marginal, 4.25 h)	50.1° 02:20	9.71	99%	35.4°
2048-02-29 Sat	24	—	unknown	02:10–05:25 (marginal, 3.25 h)	50.1° 02:15	9.66	100%	22.7°
2048-03-01 Sun	25	—	unknown	22:45–05:25 (marginal, 6.67 h)	50.1° 02:10	9.62	98%	11.8°
2048-03-02 Mon	29	—	unknown	22:15–05:20 (marginal, 7.08 h)	50.1° 02:05	9.57	93%	12.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-02-02&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.