{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":4.17,"best_label":"marginal","best_window":"19:00\u201323:10","dark_hours":11.09,"date":"2043-01-21","moon_free_dark_hours":0.7,"moon_illumination":86,"moon_separation":55.1,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":89.5,"transit_local":"17:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.08,"best_label":"marginal","best_window":"19:05\u201323:10","dark_hours":11.06,"date":"2043-01-22","moon_free_dark_hours":0.0,"moon_illumination":93,"moon_separation":66.3,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":89.7,"transit_local":"17:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.83,"best_label":"good","best_window":"19:05\u201319:55","dark_hours":11.03,"date":"2043-01-23","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":77.9,"score":null,"score_astronomy":40,"score_weather":null,"transit_alt":89.8,"transit_local":"16:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.0,"best_label":"good","best_window":"19:05\u201321:05","dark_hours":11.0,"date":"2043-01-24","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":89.5,"score":null,"score_astronomy":51,"score_weather":null,"transit_alt":89.8,"transit_local":"16:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.25,"best_label":"good","best_window":"19:05\u201322:20","dark_hours":10.98,"date":"2043-01-25","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":101.0,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":89.6,"transit_local":"16:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.42,"best_label":"good","best_window":"19:05\u201322:30","dark_hours":10.95,"date":"2043-01-26","moon_free_dark_hours":0.0,"moon_illumination":97,"moon_separation":112.0,"score":null,"score_astronomy":76,"score_weather":null,"transit_alt":89.6,"transit_local":"16:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.42,"best_label":"good","best_window":"19:10\u201322:35","dark_hours":10.92,"date":"2043-01-27","moon_free_dark_hours":0.87,"moon_illumination":92,"moon_separation":122.3,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":89.7,"transit_local":"16:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.42,"best_label":"good","best_window":"19:10\u201322:35","dark_hours":10.89,"date":"2043-01-28","moon_free_dark_hours":1.93,"moon_illumination":86,"moon_separation":131.7,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":89.8,"transit_local":"16:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":3.42,"best_label":"good","best_window":"19:10\u201322:35","dark_hours":10.86,"date":"2043-01-29","moon_free_dark_hours":2.97,"moon_illumination":79,"moon_separation":139.7,"score":null,"score_astronomy":91,"score_weather":null,"transit_alt":89.7,"transit_local":"16:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.42,"best_label":"good","best_window":"19:10\u201322:35","dark_hours":10.83,"date":"2043-01-30","moon_free_dark_hours":3.98,"moon_illumination":70,"moon_separation":145.6,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":89.5,"transit_local":"16:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.25,"best_label":"good","best_window":"19:15\u201322:30","dark_hours":10.79,"date":"2043-01-31","moon_free_dark_hours":5.0,"moon_illumination":62,"moon_separation":148.2,"score":null,"score_astronomy":86,"score_weather":null,"transit_alt":89.6,"transit_local":"16:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.25,"best_label":"good","best_window":"19:15\u201322:30","dark_hours":10.76,"date":"2043-02-01","moon_free_dark_hours":6.03,"moon_illumination":52,"moon_separation":147.0,"score":null,"score_astronomy":84,"score_weather":null,"transit_alt":89.8,"transit_local":"16:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.17,"best_label":"good","best_window":"19:15\u201322:25","dark_hours":10.73,"date":"2043-02-02","moon_free_dark_hours":7.08,"moon_illumination":43,"moon_separation":142.4,"score":null,"score_astronomy":82,"score_weather":null,"transit_alt":89.8,"transit_local":"16:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.08,"best_label":"good","best_window":"19:15\u201322:20","dark_hours":10.69,"date":"2043-02-03","moon_free_dark_hours":8.15,"moon_illumination":34,"moon_separation":135.3,"score":null,"score_astronomy":79,"score_weather":null,"transit_alt":89.7,"transit_local":"16:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.0,"best_label":"good","best_window":"19:15\u201322:15","dark_hours":10.66,"date":"2043-02-04","moon_free_dark_hours":9.18,"moon_illumination":25,"moon_separation":126.6,"score":null,"score_astronomy":77,"score_weather":null,"transit_alt":89.5,"transit_local":"16:10","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.92,"best_label":"good","best_window":"19:20\u201322:15","dark_hours":10.63,"date":"2043-02-05","moon_free_dark_hours":10.15,"moon_illumination":17,"moon_separation":116.9,"score":null,"score_astronomy":73,"score_weather":null,"transit_alt":89.7,"transit_local":"16:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.83,"best_label":"good","best_window":"19:20\u201322:10","dark_hours":10.59,"date":"2043-02-06","moon_free_dark_hours":10.57,"moon_illumination":10,"moon_separation":106.4,"score":null,"score_astronomy":71,"score_weather":null,"transit_alt":89.8,"transit_local":"16:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.75,"best_label":"good","best_window":"19:20\u201322:05","dark_hours":10.55,"date":"2043-02-07","moon_free_dark_hours":10.53,"moon_illumination":5,"moon_separation":95.4,"score":null,"score_astronomy":69,"score_weather":null,"transit_alt":89.8,"transit_local":"15:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.67,"best_label":"good","best_window":"19:20\u201322:00","dark_hours":10.52,"date":"2043-02-08","moon_free_dark_hours":10.5,"moon_illumination":1,"moon_separation":84.0,"score":null,"score_astronomy":67,"score_weather":null,"transit_alt":89.6,"transit_local":"15:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.5,"best_label":"good","best_window":"19:25\u201321:55","dark_hours":10.48,"date":"2043-02-09","moon_free_dark_hours":10.47,"moon_illumination":0,"moon_separation":72.4,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":89.6,"transit_local":"15:50","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.5,"best_label":"good","best_window":"19:25\u201321:55","dark_hours":10.44,"date":"2043-02-10","moon_free_dark_hours":10.43,"moon_illumination":2,"moon_separation":60.9,"score":null,"score_astronomy":62,"score_weather":null,"transit_alt":89.7,"transit_local":"15:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.42,"best_label":"good","best_window":"19:25\u201321:50","dark_hours":10.41,"date":"2043-02-11","moon_free_dark_hours":10.12,"moon_illumination":5,"moon_separation":50.0,"score":null,"score_astronomy":58,"score_weather":null,"transit_alt":89.8,"transit_local":"15:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.33,"best_label":"good","best_window":"19:25\u201321:45","dark_hours":10.37,"date":"2043-02-12","moon_free_dark_hours":8.85,"moon_illumination":12,"moon_separation":40.4,"score":null,"score_astronomy":53,"score_weather":null,"transit_alt":89.7,"transit_local":"15:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.0,"best_label":"good","best_window":"19:30\u201321:30","dark_hours":10.33,"date":"2043-02-13","moon_free_dark_hours":7.58,"moon_illumination":20,"moon_separation":33.7,"score":null,"score_astronomy":44,"score_weather":null,"transit_alt":89.5,"transit_local":"15:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.83,"best_label":"good","best_window":"19:30\u201321:20","dark_hours":10.29,"date":"2043-02-14","moon_free_dark_hours":6.3,"moon_illumination":30,"moon_separation":31.6,"score":null,"score_astronomy":35,"score_weather":null,"transit_alt":89.6,"transit_local":"15:30","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.33,"best_label":"good","best_window":"19:30\u201320:50","dark_hours":10.25,"date":"2043-02-15","moon_free_dark_hours":5.0,"moon_illumination":41,"moon_separation":35.1,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":89.8,"transit_local":"15:25","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.42,"best_label":"marginal","best_window":"19:30\u201321:55","dark_hours":10.21,"date":"2043-02-16","moon_free_dark_hours":3.7,"moon_illumination":53,"moon_separation":42.7,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":89.8,"transit_local":"15:20","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.25,"best_label":"marginal","best_window":"19:30\u201321:45","dark_hours":10.17,"date":"2043-02-17","moon_free_dark_hours":2.43,"moon_illumination":64,"moon_separation":52.4,"score":null,"score_astronomy":17,"score_weather":null,"transit_alt":89.7,"transit_local":"15:15","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.0,"best_label":"marginal","best_window":"19:35\u201321:35","dark_hours":10.13,"date":"2043-02-18","moon_free_dark_hours":1.32,"moon_illumination":74,"moon_separation":63.2,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":89.5,"transit_local":"15:15","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.0,"best_label":"marginal","best_window":"19:35\u201321:35","dark_hours":10.09,"date":"2043-02-19","moon_free_dark_hours":0.37,"moon_illumination":83,"moon_separation":74.5,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":89.7,"transit_local":"15:10","verdict":"unknown","weather_source":"none","weekday":"Thu"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2043-01-21","target":{"common_name":"Andromeda Galaxy","dec":41.26875,"morphology":"SA(s)b","name":"M 31","ra":10.68470833,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=M31","source":"sesame","type":"AGN","type_text":"galaxy with an active nucleus","vmag":3.44}}