{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":7.58,"best_label":"good","best_window":"20:45\u201304:20","dark_hours":8.33,"date":"2041-03-27","moon_free_dark_hours":8.32,"moon_illumination":23,"moon_separation":125.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:30","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.58,"best_label":"good","best_window":"20:40\u201304:15","dark_hours":8.28,"date":"2041-03-28","moon_free_dark_hours":8.25,"moon_illumination":14,"moon_separation":139.6,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.67,"best_label":"good","best_window":"20:35\u201304:15","dark_hours":8.23,"date":"2041-03-29","moon_free_dark_hours":8.22,"moon_illumination":7,"moon_separation":154.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:20","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.67,"best_label":"good","best_window":"20:30\u201305:10","dark_hours":8.17,"date":"2041-03-30","moon_free_dark_hours":8.17,"moon_illumination":2,"moon_separation":169.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":7.67,"best_label":"good","best_window":"21:25\u201305:05","dark_hours":8.12,"date":"2041-03-31","moon_free_dark_hours":8.1,"moon_illumination":0,"moon_separation":175.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"01:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":7.58,"best_label":"good","best_window":"21:25\u201305:00","dark_hours":8.06,"date":"2041-04-01","moon_free_dark_hours":8.05,"moon_illumination":1,"moon_separation":161.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"01:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":7.5,"best_label":"good","best_window":"21:25\u201304:55","dark_hours":8.01,"date":"2041-04-02","moon_free_dark_hours":7.85,"moon_illumination":5,"moon_separation":147.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"01:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":7.42,"best_label":"good","best_window":"21:30\u201304:55","dark_hours":7.95,"date":"2041-04-03","moon_free_dark_hours":6.58,"moon_illumination":10,"moon_separation":133.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"01:00","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.33,"best_label":"good","best_window":"21:30\u201304:50","dark_hours":7.9,"date":"2041-04-04","moon_free_dark_hours":5.37,"moon_illumination":18,"moon_separation":120.1,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"01:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.25,"best_label":"good","best_window":"21:30\u201304:45","dark_hours":7.84,"date":"2041-04-05","moon_free_dark_hours":4.2,"moon_illumination":26,"moon_separation":107.1,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.17,"best_label":"good","best_window":"21:30\u201304:40","dark_hours":7.78,"date":"2041-04-06","moon_free_dark_hours":3.15,"moon_illumination":36,"moon_separation":94.6,"score":null,"score_astronomy":91,"score_weather":null,"transit_alt":50.1,"transit_local":"00:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":7.08,"best_label":"good","best_window":"21:35\u201304:40","dark_hours":7.73,"date":"2041-04-07","moon_free_dark_hours":2.23,"moon_illumination":46,"moon_separation":82.3,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":50.1,"transit_local":"00:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.83,"best_label":"good","best_window":"21:45\u201304:35","dark_hours":7.67,"date":"2041-04-08","moon_free_dark_hours":1.47,"moon_illumination":55,"moon_separation":70.3,"score":null,"score_astronomy":82,"score_weather":null,"transit_alt":50.1,"transit_local":"00:40","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.67,"best_label":"good","best_window":"23:30\u201304:10","dark_hours":7.62,"date":"2041-04-09","moon_free_dark_hours":0.83,"moon_illumination":64,"moon_separation":58.4,"score":null,"score_astronomy":66,"score_weather":null,"transit_alt":50.1,"transit_local":"00:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":7.25,"best_label":"marginal","best_window":"21:40\u201304:55","dark_hours":7.56,"date":"2041-04-10","moon_free_dark_hours":0.3,"moon_illumination":73,"moon_separation":46.6,"score":null,"score_astronomy":56,"score_weather":null,"transit_alt":50.1,"transit_local":"00:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":7.0,"best_label":"marginal","best_window":"21:40\u201304:40","dark_hours":7.5,"date":"2041-04-11","moon_free_dark_hours":0.0,"moon_illumination":81,"moon_separation":34.8,"score":null,"score_astronomy":38,"score_weather":null,"transit_alt":50.1,"transit_local":"00:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":6.67,"best_label":"marginal","best_window":"21:50\u201304:30","dark_hours":7.44,"date":"2041-04-12","moon_free_dark_hours":0.0,"moon_illumination":88,"moon_separation":22.9,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":50.1,"transit_local":"00:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.58,"best_label":"marginal","best_window":"23:40\u201304:15","dark_hours":7.39,"date":"2041-04-13","moon_free_dark_hours":0.0,"moon_illumination":94,"moon_separation":10.9,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":50.1,"transit_local":"00:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.33,"best_label":"marginal","best_window":"00:40\u201304:00","dark_hours":7.33,"date":"2041-04-14","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":2.1,"score":null,"score_astronomy":19,"score_weather":null,"transit_alt":50.1,"transit_local":"00:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.0,"best_label":"marginal","best_window":"21:45\u201303:45","dark_hours":7.27,"date":"2041-04-15","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":14.0,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":50.1,"transit_local":"00:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":5.92,"best_label":"marginal","best_window":"21:45\u201303:40","dark_hours":7.21,"date":"2041-04-16","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":26.7,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":50.1,"transit_local":"00:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.08,"best_label":"marginal","best_window":"21:50\u201303:55","dark_hours":7.16,"date":"2041-04-17","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":39.6,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":50.1,"transit_local":"00:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.0,"best_label":"good","best_window":"21:50\u201323:50","dark_hours":7.1,"date":"2041-04-18","moon_free_dark_hours":0.75,"moon_illumination":94,"moon_separation":52.7,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":50.1,"transit_local":"00:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.42,"best_label":"good","best_window":"21:50\u201302:15","dark_hours":7.04,"date":"2041-04-19","moon_free_dark_hours":1.92,"moon_illumination":88,"moon_separation":66.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"00:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.42,"best_label":"good","best_window":"21:55\u201303:20","dark_hours":6.98,"date":"2041-04-20","moon_free_dark_hours":3.05,"moon_illumination":79,"moon_separation":79.5,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":5.58,"best_label":"good","best_window":"21:55\u201303:30","dark_hours":6.92,"date":"2041-04-21","moon_free_dark_hours":4.08,"moon_illumination":70,"moon_separation":93.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.58,"best_label":"good","best_window":"21:55\u201303:30","dark_hours":6.87,"date":"2041-04-22","moon_free_dark_hours":4.97,"moon_illumination":59,"moon_separation":107.1,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":5.67,"best_label":"good","best_window":"21:55\u201303:35","dark_hours":6.81,"date":"2041-04-23","moon_free_dark_hours":5.68,"moon_illumination":48,"moon_separation":121.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":5.5,"best_label":"good","best_window":"22:00\u201303:30","dark_hours":6.75,"date":"2041-04-24","moon_free_dark_hours":6.25,"moon_illumination":36,"moon_separation":135.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.42,"best_label":"good","best_window":"22:00\u201303:25","dark_hours":6.69,"date":"2041-04-25","moon_free_dark_hours":6.68,"moon_illumination":26,"moon_separation":149.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.1,"transit_local":"23:35","verdict":"unknown","weather_source":"none","weekday":"Thu"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2041-03-27","target":{"dec":2.05238823,"morphology":"E3","name":"3C 273","ra":187.27791594,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=3C%20273","source":"sesame","type":"BLL","type_text":"BL Lac object \u2014 a blazar","vmag":14.83}}