{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":3.0,"best_label":"good","best_window":"21:00\u201300:00","dark_hours":11.18,"date":"2026-01-17","moon_free_dark_hours":11.17,"moon_illumination":1,"moon_separation":139.6,"score":67,"score_astronomy":89,"score_weather":76,"transit_alt":42.9,"transit_local":"22:10","verdict":"marginal","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":132.1,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"22:05","verdict":"unusable","weather_source":"history","weekday":"Sun"},{"best_hours":4.58,"best_label":"good","best_window":"20:35\u201301:10","dark_hours":11.13,"date":"2026-01-19","moon_free_dark_hours":11.12,"moon_illumination":1,"moon_separation":123.2,"score":82,"score_astronomy":89,"score_weather":93,"transit_alt":42.9,"transit_local":"22:00","verdict":"good","weather_source":"history","weekday":"Mon"},{"best_hours":4.0,"best_label":"good","best_window":"19:00\u201323:00","dark_hours":11.11,"date":"2026-01-20","moon_free_dark_hours":11.08,"moon_illumination":5,"moon_separation":113.2,"score":55,"score_astronomy":89,"score_weather":61,"transit_alt":42.9,"transit_local":"21:55","verdict":"marginal","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":102.6,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"21:55","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":91.7,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"21:50","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":80.5,"score":36,"score_astronomy":88,"score_weather":41,"transit_alt":42.9,"transit_local":"21:45","verdict":"poor","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":69.3,"score":5,"score_astronomy":84,"score_weather":6,"transit_alt":42.9,"transit_local":"21:40","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":58.5,"score":0,"score_astronomy":70,"score_weather":0,"transit_alt":42.9,"transit_local":"21:35","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":48.4,"score":0,"score_astronomy":55,"score_weather":0,"transit_alt":42.9,"transit_local":"21:35","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":39.9,"score":4,"score_astronomy":36,"score_weather":11,"transit_alt":42.9,"transit_local":"21:30","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":34.6,"score":0,"score_astronomy":21,"score_weather":0,"transit_alt":42.9,"transit_local":"21:25","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":34.2,"score":0,"score_astronomy":14,"score_weather":0,"transit_alt":42.9,"transit_local":"21:20","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":38.9,"score":0,"score_astronomy":15,"score_weather":0,"transit_alt":42.9,"transit_local":"21:15","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":47.2,"score":0,"score_astronomy":20,"score_weather":0,"transit_alt":42.9,"transit_local":"21:15","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":57.3,"score":0,"score_astronomy":30,"score_weather":0,"transit_alt":42.9,"transit_local":"21:10","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":68.2,"score":0,"score_astronomy":44,"score_weather":0,"transit_alt":42.9,"transit_local":"21:05","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":79.3,"score":6,"score_astronomy":77,"score_weather":7,"transit_alt":42.9,"transit_local":"21:00","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":90.3,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"21:00","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":101.0,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:55","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":111.2,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:50","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":3.67,"best_label":"good","best_window":"19:20\u201323:00","dark_hours":10.55,"date":"2026-02-07","moon_free_dark_hours":4.77,"moon_illumination":65,"moon_separation":120.8,"score":72,"score_astronomy":89,"score_weather":81,"transit_alt":42.9,"transit_local":"20:45","verdict":"good","weather_source":"history","weekday":"Sat"},{"best_hours":1.0,"best_label":"marginal","best_window":"21:00\u201322:00","dark_hours":10.51,"date":"2026-02-08","moon_free_dark_hours":5.82,"moon_illumination":56,"moon_separation":129.6,"score":33,"score_astronomy":89,"score_weather":37,"transit_alt":42.9,"transit_local":"20:40","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":137.2,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:40","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":143.0,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:35","verdict":"unusable","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.4,"date":"2026-02-11","moon_free_dark_hours":8.85,"moon_illumination":28,"moon_separation":146.0,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:30","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.36,"date":"2026-02-12","moon_free_dark_hours":9.68,"moon_illumination":20,"moon_separation":145.5,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:25","verdict":"unusable","weather_source":"history","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.32,"date":"2026-02-13","moon_free_dark_hours":10.3,"moon_illumination":13,"moon_separation":141.5,"score":0,"score_astronomy":89,"score_weather":0,"transit_alt":42.9,"transit_local":"20:20","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":0.92,"best_label":"marginal","best_window":"23:00\u201323:55","dark_hours":10.29,"date":"2026-02-14","moon_free_dark_hours":10.27,"moon_illumination":7,"moon_separation":134.8,"score":15,"score_astronomy":89,"score_weather":17,"transit_alt":42.9,"transit_local":"20:20","verdict":"poor","weather_source":"history","weekday":"Sat"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":10.25,"date":"2026-02-15","moon_free_dark_hours":10.23,"moon_illumination":3,"moon_separation":126.2,"score":0,"score_astronomy":88,"score_weather":0,"transit_alt":42.9,"transit_local":"20:15","verdict":"unusable","weather_source":"history","weekday":"Sun"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2026-01-17","target":{"common_name":"Great Orion Nebula","dec":-5.3876,"name":"M 42","ra":83.8201,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=M42","source":"sesame","type":"HII","type_text":"HII region \u2014 a star-forming nebula"}}
