{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":4.75,"best_label":"good","best_window":"19:00\u201323:45","dark_hours":11.29,"date":"2026-01-12","moon_free_dark_hours":8.53,"moon_illumination":29,"moon_separation":146.0,"score":95,"score_astronomy":100,"score_weather":95,"transit_alt":89.6,"transit_local":"17:35","verdict":"good","weather_source":"history","weekday":"Mon"},{"best_hours":0.42,"best_label":"marginal","best_window":"23:00\u201323:25","dark_hours":11.27,"date":"2026-01-13","moon_free_dark_hours":9.57,"moon_illumination":21,"moon_separation":139.2,"score":6,"score_astronomy":100,"score_weather":6,"transit_alt":89.5,"transit_local":"17:35","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":4.67,"best_label":"good","best_window":"18:55\u201323:35","dark_hours":11.25,"date":"2026-01-14","moon_free_dark_hours":10.57,"moon_illumination":14,"moon_separation":130.7,"score":99,"score_astronomy":100,"score_weather":99,"transit_alt":89.6,"transit_local":"17:30","verdict":"good","weather_source":"history","weekday":"Wed"},{"best_hours":4.08,"best_label":"good","best_window":"18:55\u201323:00","dark_hours":11.23,"date":"2026-01-15","moon_free_dark_hours":11.22,"moon_illumination":8,"moon_separation":121.3,"score":88,"score_astronomy":100,"score_weather":88,"transit_alt":89.7,"transit_local":"17:25","verdict":"good","weather_source":"history","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":11.2,"date":"2026-01-16","moon_free_dark_hours":11.18,"moon_illumination":4,"moon_separation":111.2,"score":0,"score_astronomy":100,"score_weather":0,"transit_alt":89.7,"transit_local":"17:20","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":4.33,"best_label":"good","best_window":"19:00\u201323:20","dark_hours":11.18,"date":"2026-01-17","moon_free_dark_hours":11.17,"moon_illumination":1,"moon_separation":100.7,"score":89,"score_astronomy":100,"score_weather":89,"transit_alt":89.5,"transit_local":"17:15","verdict":"good","weather_source":"history","weekday":"Sat"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":11.16,"date":"2026-01-18","moon_free_dark_hours":11.15,"moon_illumination":0,"moon_separation":89.9,"score":0,"score_astronomy":100,"score_weather":0,"transit_alt":89.5,"transit_local":"17:15","verdict":"unusable","weather_source":"history","weekday":"Sun"},{"best_hours":4.33,"best_label":"good","best_window":"19:00\u201323:20","dark_hours":11.13,"date":"2026-01-19","moon_free_dark_hours":11.12,"moon_illumination":1,"moon_separation":78.9,"score":92,"score_astronomy":100,"score_weather":92,"transit_alt":89.7,"transit_local":"17:10","verdict":"good","weather_source":"history","weekday":"Mon"},{"best_hours":3.42,"best_label":"good","best_window":"19:00\u201322:25","dark_hours":11.11,"date":"2026-01-20","moon_free_dark_hours":11.08,"moon_illumination":5,"moon_separation":67.9,"score":83,"score_astronomy":100,"score_weather":83,"transit_alt":89.7,"transit_local":"17:05","verdict":"good","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":11.08,"date":"2026-01-21","moon_free_dark_hours":9.92,"moon_illumination":10,"moon_separation":57.1,"score":0,"score_astronomy":97,"score_weather":0,"transit_alt":89.6,"transit_local":"17:00","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":11.06,"date":"2026-01-22","moon_free_dark_hours":8.78,"moon_illumination":17,"moon_separation":46.8,"score":0,"score_astronomy":92,"score_weather":0,"transit_alt":89.5,"transit_local":"16:55","verdict":"unusable","weather_source":"history","weekday":"Thu"},{"best_hours":1.92,"best_label":"good","best_window":"19:05\u201321:00","dark_hours":11.03,"date":"2026-01-23","moon_free_dark_hours":7.6,"moon_illumination":26,"moon_separation":37.7,"score":43,"score_astronomy":79,"score_weather":54,"transit_alt":89.6,"transit_local":"16:55","verdict":"marginal","weather_source":"history","weekday":"Fri"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":11.0,"date":"2026-01-24","moon_free_dark_hours":6.43,"moon_illumination":36,"moon_separation":31.2,"score":5,"score_astronomy":61,"score_weather":9,"transit_alt":89.7,"transit_local":"16:50","verdict":"poor","weather_source":"history","weekday":"Sat"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.97,"date":"2026-01-25","moon_free_dark_hours":5.18,"moon_illumination":47,"moon_separation":29.5,"score":0,"score_astronomy":45,"score_weather":0,"transit_alt":89.7,"transit_local":"16:45","verdict":"unusable","weather_source":"history","weekday":"Sun"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.94,"date":"2026-01-26","moon_free_dark_hours":3.88,"moon_illumination":58,"moon_separation":33.5,"score":0,"score_astronomy":33,"score_weather":0,"transit_alt":89.6,"transit_local":"16:40","verdict":"unusable","weather_source":"history","weekday":"Mon"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.91,"date":"2026-01-27","moon_free_dark_hours":2.6,"moon_illumination":69,"moon_separation":41.8,"score":4,"score_astronomy":26,"score_weather":17,"transit_alt":89.5,"transit_local":"16:40","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.88,"date":"2026-01-28","moon_free_dark_hours":1.35,"moon_illumination":80,"moon_separation":52.4,"score":0,"score_astronomy":24,"score_weather":0,"transit_alt":89.6,"transit_local":"16:35","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.85,"date":"2026-01-29","moon_free_dark_hours":0.23,"moon_illumination":88,"moon_separation":64.2,"score":0,"score_astronomy":26,"score_weather":0,"transit_alt":89.7,"transit_local":"16:30","verdict":"unusable","weather_source":"history","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.82,"date":"2026-01-30","moon_free_dark_hours":0.0,"moon_illumination":95,"moon_separation":76.6,"score":0,"score_astronomy":33,"score_weather":0,"transit_alt":89.7,"transit_local":"16:25","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.79,"date":"2026-01-31","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":89.2,"score":0,"score_astronomy":41,"score_weather":0,"transit_alt":89.5,"transit_local":"16:20","verdict":"unusable","weather_source":"history","weekday":"Sat"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.76,"date":"2026-02-01","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":101.6,"score":0,"score_astronomy":51,"score_weather":0,"transit_alt":89.5,"transit_local":"16:20","verdict":"unusable","weather_source":"history","weekday":"Sun"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.72,"date":"2026-02-02","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":113.6,"score":0,"score_astronomy":61,"score_weather":0,"transit_alt":89.7,"transit_local":"16:15","verdict":"unusable","weather_source":"history","weekday":"Mon"},{"best_hours":0.25,"best_label":"marginal","best_window":"18:45\u201319:00","dark_hours":10.69,"date":"2026-02-03","moon_free_dark_hours":0.42,"moon_illumination":95,"moon_separation":124.8,"score":8,"score_astronomy":72,"score_weather":10,"transit_alt":89.7,"transit_local":"16:10","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.66,"date":"2026-02-04","moon_free_dark_hours":1.53,"moon_illumination":89,"moon_separation":135.0,"score":0,"score_astronomy":73,"score_weather":0,"transit_alt":89.6,"transit_local":"16:05","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.62,"date":"2026-02-05","moon_free_dark_hours":2.63,"moon_illumination":82,"moon_separation":143.4,"score":0,"score_astronomy":72,"score_weather":0,"transit_alt":89.5,"transit_local":"16:00","verdict":"unusable","weather_source":"history","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.59,"date":"2026-02-06","moon_free_dark_hours":3.7,"moon_illumination":74,"moon_separation":149.0,"score":0,"score_astronomy":71,"score_weather":0,"transit_alt":89.6,"transit_local":"16:00","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":2.67,"best_label":"good","best_window":"19:20\u201322:00","dark_hours":10.55,"date":"2026-02-07","moon_free_dark_hours":4.77,"moon_illumination":65,"moon_separation":150.6,"score":61,"score_astronomy":68,"score_weather":90,"transit_alt":89.7,"transit_local":"15:55","verdict":"marginal","weather_source":"history","weekday":"Sat"},{"best_hours":0.42,"best_label":"good","best_window":"19:20\u201319:45","dark_hours":10.51,"date":"2026-02-08","moon_free_dark_hours":5.82,"moon_illumination":56,"moon_separation":147.8,"score":25,"score_astronomy":66,"score_weather":38,"transit_alt":89.7,"transit_local":"15:50","verdict":"poor","weather_source":"history","weekday":"Sun"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.48,"date":"2026-02-09","moon_free_dark_hours":6.88,"moon_illumination":46,"moon_separation":141.7,"score":0,"score_astronomy":63,"score_weather":0,"transit_alt":89.6,"transit_local":"15:45","verdict":"unusable","weather_source":"history","weekday":"Mon"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.44,"date":"2026-02-10","moon_free_dark_hours":7.9,"moon_illumination":37,"moon_separation":133.7,"score":0,"score_astronomy":61,"score_weather":0,"transit_alt":89.5,"transit_local":"15:45","verdict":"unusable","weather_source":"history","weekday":"Tue"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2026-01-12","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}}
