{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":0.25,"best_label":"marginal","best_window":"04:50\u201305:05","dark_hours":7.26,"date":"2027-08-26","moon_free_dark_hours":3.33,"moon_illumination":30,"moon_separation":32.6,"score":null,"score_astronomy":3,"score_weather":null,"transit_alt":42.9,"transit_local":"08:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.25,"best_label":"marginal","best_window":"04:50\u201305:05","dark_hours":7.32,"date":"2027-08-27","moon_free_dark_hours":4.53,"moon_illumination":20,"moon_separation":36.0,"score":null,"score_astronomy":4,"score_weather":null,"transit_alt":42.9,"transit_local":"08:35","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.33,"best_label":"marginal","best_window":"04:45\u201305:05","dark_hours":7.37,"date":"2027-08-28","moon_free_dark_hours":5.87,"moon_illumination":11,"moon_separation":43.7,"score":null,"score_astronomy":5,"score_weather":null,"transit_alt":42.9,"transit_local":"08:30","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.08,"best_label":"marginal","best_window":"04:40\u201305:45","dark_hours":7.43,"date":"2027-08-29","moon_free_dark_hours":7.25,"moon_illumination":5,"moon_separation":54.1,"score":null,"score_astronomy":7,"score_weather":null,"transit_alt":42.9,"transit_local":"08:25","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.08,"best_label":"good","best_window":"05:05\u201305:10","dark_hours":7.49,"date":"2027-08-30","moon_free_dark_hours":7.47,"moon_illumination":1,"moon_separation":65.9,"score":null,"score_astronomy":9,"score_weather":null,"transit_alt":42.9,"transit_local":"08:20","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.08,"best_label":"good","best_window":"05:05\u201305:10","dark_hours":7.54,"date":"2027-08-31","moon_free_dark_hours":7.52,"moon_illumination":0,"moon_separation":78.3,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":42.9,"transit_local":"08:15","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.17,"best_label":"good","best_window":"05:00\u201305:10","dark_hours":7.6,"date":"2027-09-01","moon_free_dark_hours":7.58,"moon_illumination":2,"moon_separation":90.8,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":42.9,"transit_local":"08:15","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.33,"best_label":"good","best_window":"04:55\u201305:15","dark_hours":7.65,"date":"2027-09-02","moon_free_dark_hours":7.63,"moon_illumination":7,"moon_separation":103.0,"score":null,"score_astronomy":14,"score_weather":null,"transit_alt":42.9,"transit_local":"08:10","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.42,"best_label":"good","best_window":"04:50\u201305:15","dark_hours":7.71,"date":"2027-09-03","moon_free_dark_hours":7.68,"moon_illumination":14,"moon_separation":114.6,"score":null,"score_astronomy":15,"score_weather":null,"transit_alt":42.9,"transit_local":"08:05","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.5,"best_label":"good","best_window":"04:45\u201305:15","dark_hours":7.76,"date":"2027-09-04","moon_free_dark_hours":7.75,"moon_illumination":22,"moon_separation":125.3,"score":null,"score_astronomy":17,"score_weather":null,"transit_alt":42.9,"transit_local":"08:00","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.5,"best_label":"good","best_window":"04:45\u201305:15","dark_hours":7.82,"date":"2027-09-05","moon_free_dark_hours":7.37,"moon_illumination":32,"moon_separation":134.7,"score":null,"score_astronomy":18,"score_weather":null,"transit_alt":42.9,"transit_local":"07:55","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.67,"best_label":"good","best_window":"04:40\u201305:20","dark_hours":7.87,"date":"2027-09-06","moon_free_dark_hours":6.73,"moon_illumination":42,"moon_separation":142.1,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":42.9,"transit_local":"07:55","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.75,"best_label":"good","best_window":"04:35\u201305:20","dark_hours":7.93,"date":"2027-09-07","moon_free_dark_hours":6.02,"moon_illumination":52,"moon_separation":146.6,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":42.9,"transit_local":"07:50","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.83,"best_label":"good","best_window":"04:30\u201305:20","dark_hours":7.98,"date":"2027-09-08","moon_free_dark_hours":5.15,"moon_illumination":61,"moon_separation":147.3,"score":null,"score_astronomy":24,"score_weather":null,"transit_alt":42.9,"transit_local":"07:45","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.83,"best_label":"good","best_window":"04:30\u201305:20","dark_hours":8.04,"date":"2027-09-09","moon_free_dark_hours":4.2,"moon_illumination":70,"moon_separation":144.3,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":42.9,"transit_local":"07:40","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.0,"best_label":"good","best_window":"04:25\u201305:25","dark_hours":8.09,"date":"2027-09-10","moon_free_dark_hours":3.22,"moon_illumination":79,"moon_separation":138.3,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":42.9,"transit_local":"07:40","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.08,"best_label":"good","best_window":"04:20\u201305:25","dark_hours":8.15,"date":"2027-09-11","moon_free_dark_hours":2.18,"moon_illumination":86,"moon_separation":130.6,"score":null,"score_astronomy":29,"score_weather":null,"transit_alt":42.9,"transit_local":"07:35","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.17,"best_label":"good","best_window":"04:15\u201305:25","dark_hours":8.2,"date":"2027-09-12","moon_free_dark_hours":1.15,"moon_illumination":92,"moon_separation":121.8,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":42.9,"transit_local":"07:30","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.0,"best_label":"good","best_window":"04:25\u201305:25","dark_hours":8.25,"date":"2027-09-13","moon_free_dark_hours":0.13,"moon_illumination":96,"moon_separation":112.3,"score":null,"score_astronomy":29,"score_weather":null,"transit_alt":42.9,"transit_local":"07:25","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.0,"best_label":"good","best_window":"04:30\u201305:30","dark_hours":8.31,"date":"2027-09-14","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":102.3,"score":null,"score_astronomy":23,"score_weather":null,"transit_alt":42.9,"transit_local":"07:20","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.67,"best_label":"good","best_window":"04:50\u201305:30","dark_hours":8.36,"date":"2027-09-15","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":92.1,"score":null,"score_astronomy":20,"score_weather":null,"transit_alt":42.9,"transit_local":"07:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.83,"best_label":"marginal","best_window":"03:40\u201305:30","dark_hours":8.41,"date":"2027-09-16","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":81.7,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":42.9,"transit_local":"07:15","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.75,"best_label":"marginal","best_window":"03:45\u201305:30","dark_hours":8.46,"date":"2027-09-17","moon_free_dark_hours":0.0,"moon_illumination":96,"moon_separation":71.3,"score":null,"score_astronomy":13,"score_weather":null,"transit_alt":42.9,"transit_local":"07:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.75,"best_label":"marginal","best_window":"03:50\u201305:35","dark_hours":8.52,"date":"2027-09-18","moon_free_dark_hours":0.0,"moon_illumination":91,"moon_separation":61.0,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":42.9,"transit_local":"07:05","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.67,"best_label":"marginal","best_window":"03:55\u201305:35","dark_hours":8.57,"date":"2027-09-19","moon_free_dark_hours":0.0,"moon_illumination":84,"moon_separation":51.2,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":42.9,"transit_local":"07:00","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.75,"best_label":"marginal","best_window":"03:50\u201305:35","dark_hours":8.62,"date":"2027-09-20","moon_free_dark_hours":0.37,"moon_illumination":76,"moon_separation":42.3,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":42.9,"transit_local":"07:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.0,"best_label":"marginal","best_window":"03:35\u201305:35","dark_hours":8.67,"date":"2027-09-21","moon_free_dark_hours":1.13,"moon_illumination":66,"moon_separation":35.6,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":42.9,"transit_local":"06:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.42,"best_label":"marginal","best_window":"03:15\u201305:40","dark_hours":8.72,"date":"2027-09-22","moon_free_dark_hours":2.08,"moon_illumination":56,"moon_separation":32.4,"score":null,"score_astronomy":17,"score_weather":null,"transit_alt":42.9,"transit_local":"06:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.67,"best_label":"marginal","best_window":"03:00\u201305:40","dark_hours":8.77,"date":"2027-09-23","moon_free_dark_hours":3.18,"moon_illumination":44,"moon_separation":34.3,"score":null,"score_astronomy":24,"score_weather":null,"transit_alt":42.9,"transit_local":"06:45","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.83,"best_label":"good","best_window":"03:50\u201305:40","dark_hours":8.82,"date":"2027-09-24","moon_free_dark_hours":4.43,"moon_illumination":33,"moon_separation":40.6,"score":null,"score_astronomy":33,"score_weather":null,"transit_alt":42.9,"transit_local":"06:45","verdict":"unknown","weather_source":"none","weekday":"Fri"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2027-08-26","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"}}