{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":4.67,"best_label":"good","best_window":"01:30\u201306:10","dark_hours":11.26,"date":"2029-01-13","moon_free_dark_hours":11.23,"moon_illumination":1,"moon_separation":98.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"05:15","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.75,"best_label":"good","best_window":"01:25\u201306:10","dark_hours":11.24,"date":"2029-01-14","moon_free_dark_hours":11.23,"moon_illumination":0,"moon_separation":111.5,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"05:10","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":4.83,"best_label":"good","best_window":"01:20\u201306:10","dark_hours":11.22,"date":"2029-01-15","moon_free_dark_hours":11.22,"moon_illumination":2,"moon_separation":123.9,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"05:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.92,"best_label":"good","best_window":"01:15\u201306:10","dark_hours":11.2,"date":"2029-01-16","moon_free_dark_hours":10.9,"moon_illumination":5,"moon_separation":136.1,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"05:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.92,"best_label":"good","best_window":"01:15\u201306:10","dark_hours":11.17,"date":"2029-01-17","moon_free_dark_hours":9.85,"moon_illumination":10,"moon_separation":147.8,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"05:00","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.0,"best_label":"good","best_window":"01:10\u201306:10","dark_hours":11.15,"date":"2029-01-18","moon_free_dark_hours":8.85,"moon_illumination":17,"moon_separation":158.9,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:55","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.08,"best_label":"good","best_window":"01:05\u201306:10","dark_hours":11.13,"date":"2029-01-19","moon_free_dark_hours":7.83,"moon_illumination":24,"moon_separation":168.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.17,"best_label":"good","best_window":"01:00\u201306:10","dark_hours":11.1,"date":"2029-01-20","moon_free_dark_hours":6.85,"moon_illumination":33,"moon_separation":168.8,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":5.08,"best_label":"good","best_window":"01:00\u201306:05","dark_hours":11.08,"date":"2029-01-21","moon_free_dark_hours":5.83,"moon_illumination":42,"moon_separation":160.5,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.08,"best_label":"good","best_window":"01:00\u201306:05","dark_hours":11.05,"date":"2029-01-22","moon_free_dark_hours":4.82,"moon_illumination":51,"moon_separation":149.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:40","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":5.17,"best_label":"good","best_window":"00:55\u201306:05","dark_hours":11.02,"date":"2029-01-23","moon_free_dark_hours":3.77,"moon_illumination":61,"moon_separation":138.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:35","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":5.17,"best_label":"good","best_window":"00:55\u201306:05","dark_hours":10.99,"date":"2029-01-24","moon_free_dark_hours":2.72,"moon_illumination":70,"moon_separation":126.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.17,"best_label":"good","best_window":"00:55\u201306:05","dark_hours":10.96,"date":"2029-01-25","moon_free_dark_hours":1.73,"moon_illumination":79,"moon_separation":113.8,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"04:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.08,"best_label":"good","best_window":"01:00\u201306:05","dark_hours":10.94,"date":"2029-01-26","moon_free_dark_hours":0.78,"moon_illumination":87,"moon_separation":101.0,"score":null,"score_astronomy":92,"score_weather":null,"transit_alt":50.2,"transit_local":"04:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.0,"best_label":"good","best_window":"02:05\u201306:05","dark_hours":10.91,"date":"2029-01-27","moon_free_dark_hours":0.0,"moon_illumination":93,"moon_separation":87.7,"score":null,"score_astronomy":73,"score_weather":null,"transit_alt":50.2,"transit_local":"04:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.08,"best_label":"good","best_window":"04:00\u201306:05","dark_hours":10.88,"date":"2029-01-28","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":74.0,"score":null,"score_astronomy":56,"score_weather":null,"transit_alt":50.2,"transit_local":"04:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.42,"best_label":"marginal","best_window":"00:35\u201306:00","dark_hours":10.84,"date":"2029-01-29","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":60.1,"score":null,"score_astronomy":40,"score_weather":null,"transit_alt":50.2,"transit_local":"04:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.83,"best_label":"marginal","best_window":"01:10\u201306:00","dark_hours":10.81,"date":"2029-01-30","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":45.9,"score":null,"score_astronomy":28,"score_weather":null,"transit_alt":50.2,"transit_local":"04:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.08,"best_label":"marginal","best_window":"02:55\u201306:00","dark_hours":10.78,"date":"2029-01-31","moon_free_dark_hours":0.27,"moon_illumination":96,"moon_separation":31.8,"score":null,"score_astronomy":20,"score_weather":null,"transit_alt":50.2,"transit_local":"04:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.5,"best_label":"marginal","best_window":"00:30\u201306:00","dark_hours":10.75,"date":"2029-02-01","moon_free_dark_hours":1.5,"moon_illumination":90,"moon_separation":18.4,"score":null,"score_astronomy":23,"score_weather":null,"transit_alt":50.2,"transit_local":"04:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":6.0,"best_label":"marginal","best_window":"00:00\u201306:00","dark_hours":10.71,"date":"2029-02-02","moon_free_dark_hours":2.73,"moon_illumination":82,"moon_separation":10.0,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":50.2,"transit_local":"03:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":6.25,"best_label":"marginal","best_window":"23:45\u201306:00","dark_hours":10.68,"date":"2029-02-03","moon_free_dark_hours":3.98,"moon_illumination":72,"moon_separation":16.8,"score":null,"score_astronomy":44,"score_weather":null,"transit_alt":50.2,"transit_local":"03:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.25,"best_label":"good","best_window":"00:05\u201304:20","dark_hours":10.65,"date":"2029-02-04","moon_free_dark_hours":5.22,"moon_illumination":61,"moon_separation":29.5,"score":null,"score_astronomy":77,"score_weather":null,"transit_alt":50.2,"transit_local":"03:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.92,"best_label":"good","best_window":"00:00\u201305:55","dark_hours":10.61,"date":"2029-02-05","moon_free_dark_hours":6.42,"moon_illumination":50,"moon_separation":42.8,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":50.2,"transit_local":"03:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":6.0,"best_label":"good","best_window":"23:55\u201305:55","dark_hours":10.58,"date":"2029-02-06","moon_free_dark_hours":7.57,"moon_illumination":39,"moon_separation":56.2,"score":null,"score_astronomy":92,"score_weather":null,"transit_alt":50.2,"transit_local":"03:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.08,"best_label":"good","best_window":"23:50\u201305:55","dark_hours":10.54,"date":"2029-02-07","moon_free_dark_hours":8.58,"moon_illumination":28,"moon_separation":69.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"03:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":6.17,"best_label":"good","best_window":"23:45\u201305:55","dark_hours":10.5,"date":"2029-02-08","moon_free_dark_hours":9.47,"moon_illumination":19,"moon_separation":82.5,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"03:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":6.08,"best_label":"good","best_window":"23:45\u201305:50","dark_hours":10.47,"date":"2029-02-09","moon_free_dark_hours":10.2,"moon_illumination":12,"moon_separation":95.3,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"03:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":6.17,"best_label":"good","best_window":"23:40\u201305:50","dark_hours":10.43,"date":"2029-02-10","moon_free_dark_hours":10.4,"moon_illumination":6,"moon_separation":107.9,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"03:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":6.25,"best_label":"good","best_window":"23:35\u201305:50","dark_hours":10.39,"date":"2029-02-11","moon_free_dark_hours":10.37,"moon_illumination":2,"moon_separation":120.3,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"03:20","verdict":"unknown","weather_source":"none","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":"2029-01-13","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}}