{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":8.83,"best_label":"good","best_window":"20:50\u201305:40","dark_hours":8.82,"date":"2027-09-24","moon_free_dark_hours":4.43,"moon_illumination":33,"moon_separation":83.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:50","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":8.83,"best_label":"good","best_window":"20:50\u201305:40","dark_hours":8.87,"date":"2027-09-25","moon_free_dark_hours":5.75,"moon_illumination":23,"moon_separation":96.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"01:45","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":9.0,"best_label":"good","best_window":"20:45\u201305:45","dark_hours":8.92,"date":"2027-09-26","moon_free_dark_hours":7.08,"moon_illumination":14,"moon_separation":108.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"01:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":9.0,"best_label":"good","best_window":"20:45\u201305:45","dark_hours":8.97,"date":"2027-09-27","moon_free_dark_hours":8.4,"moon_illumination":7,"moon_separation":121.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:40","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":9.0,"best_label":"good","best_window":"20:45\u201305:45","dark_hours":9.02,"date":"2027-09-28","moon_free_dark_hours":9.0,"moon_illumination":2,"moon_separation":133.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:35","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":9.08,"best_label":"good","best_window":"20:40\u201305:45","dark_hours":9.07,"date":"2027-09-29","moon_free_dark_hours":9.05,"moon_illumination":0,"moon_separation":143.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"01:30","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":9.08,"best_label":"good","best_window":"20:40\u201305:45","dark_hours":9.12,"date":"2027-09-30","moon_free_dark_hours":9.1,"moon_illumination":1,"moon_separation":150.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"01:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":9.17,"best_label":"good","best_window":"20:40\u201305:50","dark_hours":9.17,"date":"2027-10-01","moon_free_dark_hours":9.15,"moon_illumination":4,"moon_separation":151.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"01:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":9.25,"best_label":"good","best_window":"20:35\u201305:50","dark_hours":9.22,"date":"2027-10-02","moon_free_dark_hours":9.2,"moon_illumination":10,"moon_separation":146.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":9.25,"best_label":"good","best_window":"20:35\u201305:50","dark_hours":9.26,"date":"2027-10-03","moon_free_dark_hours":9.25,"moon_illumination":17,"moon_separation":138.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":9.25,"best_label":"good","best_window":"20:35\u201305:50","dark_hours":9.31,"date":"2027-10-04","moon_free_dark_hours":8.67,"moon_illumination":26,"moon_separation":129.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"01:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":9.42,"best_label":"good","best_window":"20:30\u201305:55","dark_hours":9.36,"date":"2027-10-05","moon_free_dark_hours":7.83,"moon_illumination":35,"moon_separation":119.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"01:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":9.42,"best_label":"good","best_window":"20:30\u201305:55","dark_hours":9.4,"date":"2027-10-06","moon_free_dark_hours":6.9,"moon_illumination":44,"moon_separation":108.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":9.42,"best_label":"good","best_window":"20:30\u201305:55","dark_hours":9.45,"date":"2027-10-07","moon_free_dark_hours":5.9,"moon_illumination":54,"moon_separation":98.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"01:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":9.5,"best_label":"good","best_window":"20:25\u201305:55","dark_hours":9.5,"date":"2027-10-08","moon_free_dark_hours":4.88,"moon_illumination":63,"moon_separation":87.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"00:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":9.5,"best_label":"good","best_window":"20:25\u201305:55","dark_hours":9.54,"date":"2027-10-09","moon_free_dark_hours":3.85,"moon_illumination":72,"moon_separation":77.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"00:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":9.25,"best_label":"good","best_window":"20:45\u201306:00","dark_hours":9.59,"date":"2027-10-10","moon_free_dark_hours":2.83,"moon_illumination":80,"moon_separation":67.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"00:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.08,"best_label":"good","best_window":"00:55\u201306:00","dark_hours":9.63,"date":"2027-10-11","moon_free_dark_hours":1.83,"moon_illumination":87,"moon_separation":57.0,"score":null,"score_astronomy":95,"score_weather":null,"transit_alt":89.7,"transit_local":"00:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.83,"best_label":"good","best_window":"05:10\u201306:00","dark_hours":9.68,"date":"2027-10-12","moon_free_dark_hours":0.82,"moon_illumination":93,"moon_separation":47.4,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":89.7,"transit_local":"00:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":9.67,"best_label":"marginal","best_window":"20:20\u201306:00","dark_hours":9.72,"date":"2027-10-13","moon_free_dark_hours":0.0,"moon_illumination":97,"moon_separation":38.6,"score":null,"score_astronomy":51,"score_weather":null,"transit_alt":89.6,"transit_local":"00:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.0,"best_label":"marginal","best_window":"02:05\u201306:05","dark_hours":9.77,"date":"2027-10-14","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":31.7,"score":null,"score_astronomy":37,"score_weather":null,"transit_alt":89.5,"transit_local":"00:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.67,"best_label":"marginal","best_window":"20:15\u201322:55","dark_hours":9.81,"date":"2027-10-15","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":28.5,"score":null,"score_astronomy":33,"score_weather":null,"transit_alt":89.6,"transit_local":"00:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.5,"best_label":"marginal","best_window":"20:15\u201323:45","dark_hours":9.85,"date":"2027-10-16","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":30.4,"score":null,"score_astronomy":37,"score_weather":null,"transit_alt":89.7,"transit_local":"00:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":7.83,"best_label":"marginal","best_window":"20:10\u201304:00","dark_hours":9.9,"date":"2027-10-17","moon_free_dark_hours":0.0,"moon_illumination":94,"moon_separation":36.8,"score":null,"score_astronomy":53,"score_weather":null,"transit_alt":89.7,"transit_local":"00:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.92,"best_label":"good","best_window":"20:10\u201322:05","dark_hours":9.94,"date":"2027-10-18","moon_free_dark_hours":0.0,"moon_illumination":88,"moon_separation":46.1,"score":null,"score_astronomy":62,"score_weather":null,"transit_alt":89.6,"transit_local":"00:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.83,"best_label":"good","best_window":"20:10\u201301:00","dark_hours":9.98,"date":"2027-10-19","moon_free_dark_hours":0.78,"moon_illumination":80,"moon_separation":56.9,"score":null,"score_astronomy":95,"score_weather":null,"transit_alt":89.5,"transit_local":"00:15","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":7.83,"best_label":"good","best_window":"20:10\u201304:00","dark_hours":10.02,"date":"2027-10-20","moon_free_dark_hours":1.83,"moon_illumination":70,"moon_separation":68.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"00:10","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":9.58,"best_label":"good","best_window":"20:05\u201305:40","dark_hours":10.07,"date":"2027-10-21","moon_free_dark_hours":3.03,"moon_illumination":59,"moon_separation":80.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"00:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":9.75,"best_label":"good","best_window":"20:05\u201305:50","dark_hours":10.11,"date":"2027-10-22","moon_free_dark_hours":4.28,"moon_illumination":48,"moon_separation":93.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"00:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":9.83,"best_label":"good","best_window":"20:05\u201305:55","dark_hours":10.15,"date":"2027-10-23","moon_free_dark_hours":5.57,"moon_illumination":36,"moon_separation":105.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"23:55","verdict":"unknown","weather_source":"none","weekday":"Sat"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2027-09-24","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}}