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: 06-04 (48), 06-05 (47), 06-06 (44), 06-07 (40), 06-08 (36) — by astronomy; check the weather when the night is within four days.

2046-06-04astronomy score per night — click a bar for that night2046-07-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-06-04 Mon	48	—	unknown	23:00–00:50 (good, 1.83 h)	50.1° 21:00	4.69	0%	107.4°
2046-06-05 Tue	47	—	unknown	23:00–00:45 (good, 1.75 h)	50.1° 20:55	4.66	2%	94.2°
2046-06-06 Wed	44	—	unknown	23:05–00:45 (good, 1.67 h)	50.1° 20:50	4.63	6%	80.8°
2046-06-07 Thu	40	—	unknown	23:05–00:40 (good, 1.58 h)	50.1° 20:45	4.6	12%	67.1°
2046-06-08 Fri	36	—	unknown	23:05–00:35 (good, 1.5 h)	50.1° 20:45	4.58	21%	53.4°
2046-06-09 Sat	30	—	unknown	23:05–00:20 (good, 1.25 h)	50.1° 20:40	4.55	31%	39.7°
2046-06-10 Sun	23	—	unknown	23:05–00:05 (good, 1.0 h)	50.1° 20:35	4.53	42%	26.2°
2046-06-11 Mon	18	—	unknown	23:10–00:50 (marginal, 1.67 h)	50.1° 20:30	4.51	53%	13.9°
2046-06-12 Tue	14	—	unknown	23:10–00:40 (marginal, 1.5 h)	50.1° 20:30	4.49	65%	10.0°
2046-06-13 Wed	11	—	unknown	23:10–00:30 (marginal, 1.33 h)	50.1° 20:25	4.48	75%	20.1°
2046-06-14 Thu	9	—	unknown	23:10–00:20 (marginal, 1.17 h)	50.1° 20:20	4.46	84%	33.2°
2046-06-15 Fri	9	—	unknown	23:10–00:20 (marginal, 1.17 h)	50.1° 20:15	4.45	92%	46.7°
2046-06-16 Sat	10	—	unknown	23:10–00:20 (marginal, 1.17 h)	50.1° 20:10	4.44	97%	60.3°
2046-06-17 Sun	13	—	unknown	23:10–00:20 (marginal, 1.17 h)	50.1° 20:10	4.43	99%	73.7°
2046-06-18 Mon	15	—	unknown	23:10–23:25 (good, 0.25 h)	50.1° 20:05	4.43	100%	87.0°
2046-06-19 Tue	17	—	unknown	23:10–23:35 (good, 0.42 h)	50.1° 20:00	4.42	98%	99.9°
2046-06-20 Wed	18	—	unknown	23:15–23:35 (good, 0.33 h)	50.1° 19:55	4.42	94%	112.5°
2046-06-21 Thu	19	—	unknown	23:15–23:35 (good, 0.33 h)	50.1° 19:50	4.42	88%	124.8°
2046-06-22 Fri	19	—	unknown	23:15–23:40 (good, 0.42 h)	50.1° 19:50	4.43	81%	136.8°
2046-06-23 Sat	17	—	unknown	23:15–23:35 (good, 0.33 h)	50.1° 19:45	4.43	73%	148.5°
2046-06-24 Sun	16	—	unknown	23:15–23:30 (good, 0.25 h)	50.1° 19:40	4.44	64%	159.5°
2046-06-25 Mon	14	—	unknown	23:15–23:30 (good, 0.25 h)	50.1° 19:35	4.45	55%	168.7°
2046-06-26 Tue	13	—	unknown	23:15–23:25 (good, 0.17 h)	50.1° 19:35	4.46	45%	169.2°
2046-06-27 Wed	12	—	unknown	23:15–23:20 (good, 0.08 h)	50.1° 19:30	4.47	36%	160.4°
2046-06-28 Thu	10	—	unknown	22:20–23:45 (marginal, 1.42 h)	50.1° 19:25	4.48	27%	149.2°
2046-06-29 Fri	10	—	unknown	22:20–23:40 (marginal, 1.33 h)	50.1° 19:20	4.5	19%	137.3°
2046-06-30 Sat	9	—	unknown	22:20–23:35 (marginal, 1.25 h)	50.1° 19:15	4.52	11%	124.9°
2046-07-01 Sun	8	—	unknown	22:20–23:05 (marginal, 0.75 h)	50.1° 19:15	4.54	6%	112.1°
2046-07-02 Mon	7	—	unknown	22:20–23:00 (marginal, 0.67 h)	50.1° 19:10	4.56	2%	98.9°
2046-07-03 Tue	6	—	unknown	22:20–22:55 (marginal, 0.58 h)	50.1° 19:05	4.59	0%	85.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-06-04&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.