{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":0.17,"best_label":"good","best_window":"22:25\u201322:35","dark_hours":6.66,"date":"2041-08-15","moon_free_dark_hours":0.47,"moon_illumination":79,"moon_separation":36.6,"score":null,"score_astronomy":61,"score_weather":null,"transit_alt":89.6,"transit_local":"04:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.58,"best_label":"good","best_window":"00:10\u201301:45","dark_hours":6.72,"date":"2041-08-16","moon_free_dark_hours":0.92,"moon_illumination":69,"moon_separation":34.2,"score":null,"score_astronomy":81,"score_weather":null,"transit_alt":89.6,"transit_local":"04:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":6.33,"best_label":"good","best_window":"22:15\u201304:35","dark_hours":6.78,"date":"2041-08-17","moon_free_dark_hours":1.4,"moon_illumination":59,"moon_separation":36.7,"score":null,"score_astronomy":84,"score_weather":null,"transit_alt":89.7,"transit_local":"04:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":6.75,"best_label":"good","best_window":"22:10\u201304:55","dark_hours":6.84,"date":"2041-08-18","moon_free_dark_hours":1.95,"moon_illumination":48,"moon_separation":42.9,"score":null,"score_astronomy":88,"score_weather":null,"transit_alt":89.8,"transit_local":"04:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.83,"best_label":"good","best_window":"22:05\u201304:55","dark_hours":6.89,"date":"2041-08-19","moon_free_dark_hours":2.58,"moon_illumination":38,"moon_separation":51.1,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":89.7,"transit_local":"04:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":6.83,"best_label":"good","best_window":"22:05\u201304:55","dark_hours":6.95,"date":"2041-08-20","moon_free_dark_hours":3.33,"moon_illumination":28,"moon_separation":60.3,"score":null,"score_astronomy":99,"score_weather":null,"transit_alt":89.6,"transit_local":"04:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.92,"best_label":"good","best_window":"22:00\u201304:55","dark_hours":7.01,"date":"2041-08-21","moon_free_dark_hours":4.2,"moon_illumination":20,"moon_separation":70.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"04:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.08,"best_label":"good","best_window":"21:55\u201305:00","dark_hours":7.07,"date":"2041-08-22","moon_free_dark_hours":5.18,"moon_illumination":12,"moon_separation":80.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"04:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.08,"best_label":"good","best_window":"21:55\u201305:00","dark_hours":7.12,"date":"2041-08-23","moon_free_dark_hours":6.23,"moon_illumination":7,"moon_separation":89.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.17,"best_label":"good","best_window":"21:50\u201305:00","dark_hours":7.18,"date":"2041-08-24","moon_free_dark_hours":7.15,"moon_illumination":3,"moon_separation":99.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"03:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":7.25,"best_label":"good","best_window":"21:50\u201305:05","dark_hours":7.24,"date":"2041-08-25","moon_free_dark_hours":7.22,"moon_illumination":1,"moon_separation":109.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"03:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":7.33,"best_label":"good","best_window":"21:45\u201305:05","dark_hours":7.29,"date":"2041-08-26","moon_free_dark_hours":7.27,"moon_illumination":0,"moon_separation":118.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"03:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":7.33,"best_label":"good","best_window":"21:45\u201305:05","dark_hours":7.35,"date":"2041-08-27","moon_free_dark_hours":7.33,"moon_illumination":2,"moon_separation":127.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":7.33,"best_label":"good","best_window":"21:45\u201305:05","dark_hours":7.41,"date":"2041-08-28","moon_free_dark_hours":7.38,"moon_illumination":5,"moon_separation":135.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.5,"best_label":"good","best_window":"21:40\u201305:10","dark_hours":7.46,"date":"2041-08-29","moon_free_dark_hours":7.43,"moon_illumination":9,"moon_separation":141.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"03:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.5,"best_label":"good","best_window":"21:40\u201305:10","dark_hours":7.52,"date":"2041-08-30","moon_free_dark_hours":7.5,"moon_illumination":16,"moon_separation":145.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"03:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.58,"best_label":"good","best_window":"21:35\u201305:10","dark_hours":7.58,"date":"2041-08-31","moon_free_dark_hours":7.18,"moon_illumination":23,"moon_separation":145.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"03:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":7.67,"best_label":"good","best_window":"21:35\u201305:15","dark_hours":7.63,"date":"2041-09-01","moon_free_dark_hours":6.82,"moon_illumination":32,"moon_separation":142.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":7.67,"best_label":"good","best_window":"21:35\u201305:15","dark_hours":7.69,"date":"2041-09-02","moon_free_dark_hours":6.33,"moon_illumination":42,"moon_separation":135.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"03:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":7.75,"best_label":"good","best_window":"21:30\u201305:15","dark_hours":7.74,"date":"2041-09-03","moon_free_dark_hours":5.75,"moon_illumination":52,"moon_separation":127.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"03:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":7.75,"best_label":"good","best_window":"21:30\u201305:15","dark_hours":7.8,"date":"2041-09-04","moon_free_dark_hours":5.0,"moon_illumination":63,"moon_separation":117.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"03:10","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.92,"best_label":"good","best_window":"21:25\u201305:20","dark_hours":7.85,"date":"2041-09-05","moon_free_dark_hours":4.02,"moon_illumination":73,"moon_separation":106.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.92,"best_label":"good","best_window":"21:25\u201305:20","dark_hours":7.91,"date":"2041-09-06","moon_free_dark_hours":2.85,"moon_illumination":83,"moon_separation":94.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.8,"transit_local":"03:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.67,"best_label":"good","best_window":"21:40\u201305:20","dark_hours":7.96,"date":"2041-09-07","moon_free_dark_hours":1.53,"moon_illumination":91,"moon_separation":82.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"02:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":5.75,"best_label":"good","best_window":"23:35\u201305:20","dark_hours":8.02,"date":"2041-09-08","moon_free_dark_hours":0.18,"moon_illumination":96,"moon_separation":70.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"02:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.92,"best_label":"good","best_window":"04:30\u201305:25","dark_hours":8.07,"date":"2041-09-09","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":58.1,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":89.7,"transit_local":"02:50","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":8.17,"best_label":"marginal","best_window":"21:15\u201305:25","dark_hours":8.13,"date":"2041-09-10","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":47.3,"score":null,"score_astronomy":52,"score_weather":null,"transit_alt":89.8,"transit_local":"02:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":8.17,"best_label":"marginal","best_window":"21:15\u201305:25","dark_hours":8.18,"date":"2041-09-11","moon_free_dark_hours":0.0,"moon_illumination":96,"moon_separation":38.9,"score":null,"score_astronomy":45,"score_weather":null,"transit_alt":89.8,"transit_local":"02:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":8.17,"best_label":"marginal","best_window":"21:15\u201305:25","dark_hours":8.23,"date":"2041-09-12","moon_free_dark_hours":0.0,"moon_illumination":91,"moon_separation":34.4,"score":null,"score_astronomy":49,"score_weather":null,"transit_alt":89.6,"transit_local":"02:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.25,"best_label":"good","best_window":"21:10\u201321:25","dark_hours":8.29,"date":"2041-09-13","moon_free_dark_hours":0.27,"moon_illumination":83,"moon_separation":35.1,"score":null,"score_astronomy":82,"score_weather":null,"transit_alt":89.5,"transit_local":"02:35","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":"2041-08-15","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}}