{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":1.67,"best_label":"good","best_window":"04:20\u201306:00","dark_hours":11.45,"date":"2028-12-09","moon_free_dark_hours":6.62,"moon_illumination":42,"moon_separation":12.9,"score":null,"score_astronomy":28,"score_weather":null,"transit_alt":50.2,"transit_local":"07:35","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.0,"best_label":"good","best_window":"04:00\u201306:00","dark_hours":11.46,"date":"2028-12-10","moon_free_dark_hours":7.83,"moon_illumination":31,"moon_separation":11.6,"score":null,"score_astronomy":37,"score_weather":null,"transit_alt":50.2,"transit_local":"07:30","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.25,"best_label":"good","best_window":"03:45\u201306:00","dark_hours":11.47,"date":"2028-12-11","moon_free_dark_hours":9.07,"moon_illumination":21,"moon_separation":22.4,"score":null,"score_astronomy":46,"score_weather":null,"transit_alt":50.2,"transit_local":"07:25","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.42,"best_label":"good","best_window":"03:35\u201306:00","dark_hours":11.48,"date":"2028-12-12","moon_free_dark_hours":10.33,"moon_illumination":12,"moon_separation":35.7,"score":null,"score_astronomy":54,"score_weather":null,"transit_alt":50.2,"transit_local":"07:20","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.58,"best_label":"good","best_window":"03:30\u201306:05","dark_hours":11.48,"date":"2028-12-13","moon_free_dark_hours":11.47,"moon_illumination":6,"moon_separation":49.4,"score":null,"score_astronomy":60,"score_weather":null,"transit_alt":50.2,"transit_local":"07:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.67,"best_label":"good","best_window":"03:25\u201306:05","dark_hours":11.49,"date":"2028-12-14","moon_free_dark_hours":11.47,"moon_illumination":2,"moon_separation":63.2,"score":null,"score_astronomy":62,"score_weather":null,"transit_alt":50.2,"transit_local":"07:15","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.67,"best_label":"good","best_window":"03:25\u201306:05","dark_hours":11.49,"date":"2028-12-15","moon_free_dark_hours":11.48,"moon_illumination":0,"moon_separation":76.8,"score":null,"score_astronomy":65,"score_weather":null,"transit_alt":50.2,"transit_local":"07:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.75,"best_label":"good","best_window":"03:20\u201306:05","dark_hours":11.5,"date":"2028-12-16","moon_free_dark_hours":11.48,"moon_illumination":1,"moon_separation":90.2,"score":null,"score_astronomy":67,"score_weather":null,"transit_alt":50.2,"transit_local":"07:05","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.83,"best_label":"good","best_window":"03:15\u201306:05","dark_hours":11.5,"date":"2028-12-17","moon_free_dark_hours":11.48,"moon_illumination":4,"moon_separation":103.2,"score":null,"score_astronomy":68,"score_weather":null,"transit_alt":50.2,"transit_local":"07:00","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.92,"best_label":"good","best_window":"03:10\u201306:05","dark_hours":11.51,"date":"2028-12-18","moon_free_dark_hours":10.75,"moon_illumination":9,"moon_separation":115.9,"score":null,"score_astronomy":69,"score_weather":null,"transit_alt":50.2,"transit_local":"07:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.0,"best_label":"good","best_window":"03:05\u201306:05","dark_hours":11.51,"date":"2028-12-19","moon_free_dark_hours":9.65,"moon_illumination":15,"moon_separation":128.3,"score":null,"score_astronomy":71,"score_weather":null,"transit_alt":50.2,"transit_local":"06:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.0,"best_label":"good","best_window":"03:05\u201306:05","dark_hours":11.51,"date":"2028-12-20","moon_free_dark_hours":8.62,"moon_illumination":23,"moon_separation":140.2,"score":null,"score_astronomy":73,"score_weather":null,"transit_alt":50.2,"transit_local":"06:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":3.08,"best_label":"good","best_window":"03:00\u201306:05","dark_hours":11.51,"date":"2028-12-21","moon_free_dark_hours":7.6,"moon_illumination":32,"moon_separation":151.7,"score":null,"score_astronomy":74,"score_weather":null,"transit_alt":50.2,"transit_local":"06:45","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.25,"best_label":"good","best_window":"02:55\u201306:10","dark_hours":11.51,"date":"2028-12-22","moon_free_dark_hours":6.62,"moon_illumination":41,"moon_separation":162.3,"score":null,"score_astronomy":77,"score_weather":null,"transit_alt":50.2,"transit_local":"06:45","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.33,"best_label":"good","best_window":"02:50\u201306:10","dark_hours":11.5,"date":"2028-12-23","moon_free_dark_hours":5.63,"moon_illumination":50,"moon_separation":169.6,"score":null,"score_astronomy":78,"score_weather":null,"transit_alt":50.2,"transit_local":"06:40","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.33,"best_label":"good","best_window":"02:50\u201306:10","dark_hours":11.5,"date":"2028-12-24","moon_free_dark_hours":4.65,"moon_illumination":60,"moon_separation":166.6,"score":null,"score_astronomy":80,"score_weather":null,"transit_alt":50.2,"transit_local":"06:35","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.42,"best_label":"good","best_window":"02:45\u201306:10","dark_hours":11.5,"date":"2028-12-25","moon_free_dark_hours":3.63,"moon_illumination":69,"moon_separation":156.9,"score":null,"score_astronomy":82,"score_weather":null,"transit_alt":50.2,"transit_local":"06:30","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.42,"best_label":"good","best_window":"02:45\u201306:10","dark_hours":11.49,"date":"2028-12-26","moon_free_dark_hours":2.6,"moon_illumination":77,"moon_separation":145.7,"score":null,"score_astronomy":82,"score_weather":null,"transit_alt":50.2,"transit_local":"06:25","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.42,"best_label":"good","best_window":"02:45\u201306:10","dark_hours":11.49,"date":"2028-12-27","moon_free_dark_hours":1.57,"moon_illumination":85,"moon_separation":133.8,"score":null,"score_astronomy":81,"score_weather":null,"transit_alt":50.2,"transit_local":"06:25","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":3.42,"best_label":"good","best_window":"02:45\u201306:10","dark_hours":11.48,"date":"2028-12-28","moon_free_dark_hours":0.53,"moon_illumination":92,"moon_separation":121.4,"score":null,"score_astronomy":80,"score_weather":null,"transit_alt":50.2,"transit_local":"06:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.33,"best_label":"good","best_window":"02:50\u201306:10","dark_hours":11.47,"date":"2028-12-29","moon_free_dark_hours":0.0,"moon_illumination":96,"moon_separation":108.7,"score":null,"score_astronomy":65,"score_weather":null,"transit_alt":50.2,"transit_local":"06:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.83,"best_label":"good","best_window":"03:20\u201306:10","dark_hours":11.47,"date":"2028-12-30","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":95.6,"score":null,"score_astronomy":54,"score_weather":null,"transit_alt":50.2,"transit_local":"06:10","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.33,"best_label":"good","best_window":"04:50\u201306:10","dark_hours":11.46,"date":"2028-12-31","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":82.2,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":50.2,"transit_local":"06:05","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.92,"best_label":"marginal","best_window":"02:15\u201306:10","dark_hours":11.45,"date":"2029-01-01","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":68.5,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":50.2,"transit_local":"06:05","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.75,"best_label":"marginal","best_window":"02:25\u201306:10","dark_hours":11.44,"date":"2029-01-02","moon_free_dark_hours":0.6,"moon_illumination":94,"moon_separation":54.7,"score":null,"score_astronomy":24,"score_weather":null,"transit_alt":50.2,"transit_local":"06:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.75,"best_label":"marginal","best_window":"02:25\u201306:10","dark_hours":11.42,"date":"2029-01-03","moon_free_dark_hours":1.82,"moon_illumination":87,"moon_separation":40.9,"score":null,"score_astronomy":20,"score_weather":null,"transit_alt":50.2,"transit_local":"05:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.0,"best_label":"marginal","best_window":"02:10\u201306:10","dark_hours":11.41,"date":"2029-01-04","moon_free_dark_hours":3.03,"moon_illumination":78,"moon_separation":27.3,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":50.2,"transit_local":"05:50","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.42,"best_label":"marginal","best_window":"01:45\u201306:10","dark_hours":11.4,"date":"2029-01-05","moon_free_dark_hours":4.23,"moon_illumination":68,"moon_separation":15.0,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":50.2,"transit_local":"05:50","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.67,"best_label":"marginal","best_window":"01:30\u201306:10","dark_hours":11.38,"date":"2029-01-06","moon_free_dark_hours":5.43,"moon_illumination":57,"moon_separation":10.4,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":50.2,"transit_local":"05:45","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.92,"best_label":"good","best_window":"02:15\u201306:10","dark_hours":11.37,"date":"2029-01-07","moon_free_dark_hours":6.63,"moon_illumination":46,"moon_separation":19.7,"score":null,"score_astronomy":55,"score_weather":null,"transit_alt":50.2,"transit_local":"05:40","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":"2028-12-09","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}}