{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":6.25,"best_label":"good","best_window":"21:45\u201304:00","dark_hours":7.22,"date":"2029-04-16","moon_free_dark_hours":6.17,"moon_illumination":8,"moon_separation":125.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"00:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":6.17,"best_label":"good","best_window":"21:50\u201304:00","dark_hours":7.16,"date":"2029-04-17","moon_free_dark_hours":5.18,"moon_illumination":14,"moon_separation":113.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"00:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.08,"best_label":"good","best_window":"21:50\u201303:55","dark_hours":7.1,"date":"2029-04-18","moon_free_dark_hours":4.27,"moon_illumination":22,"moon_separation":100.9,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"00:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":6.0,"best_label":"good","best_window":"21:50\u201303:50","dark_hours":7.05,"date":"2029-04-19","moon_free_dark_hours":3.45,"moon_illumination":31,"moon_separation":88.5,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":50.2,"transit_local":"00:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.92,"best_label":"good","best_window":"21:50\u201303:45","dark_hours":6.99,"date":"2029-04-20","moon_free_dark_hours":2.73,"moon_illumination":40,"moon_separation":75.8,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":50.2,"transit_local":"23:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.83,"best_label":"good","best_window":"21:55\u201303:45","dark_hours":6.93,"date":"2029-04-21","moon_free_dark_hours":2.1,"moon_illumination":51,"moon_separation":62.9,"score":null,"score_astronomy":83,"score_weather":null,"transit_alt":50.2,"transit_local":"23:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.67,"best_label":"good","best_window":"23:00\u201303:40","dark_hours":6.87,"date":"2029-04-22","moon_free_dark_hours":1.55,"moon_illumination":62,"moon_separation":49.6,"score":null,"score_astronomy":75,"score_weather":null,"transit_alt":50.2,"transit_local":"23:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.17,"best_label":"marginal","best_window":"21:55\u201304:05","dark_hours":6.81,"date":"2029-04-23","moon_free_dark_hours":1.02,"moon_illumination":73,"moon_separation":36.0,"score":null,"score_astronomy":46,"score_weather":null,"transit_alt":50.2,"transit_local":"23:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":5.83,"best_label":"marginal","best_window":"22:00\u201303:50","dark_hours":6.75,"date":"2029-04-24","moon_free_dark_hours":0.52,"moon_illumination":82,"moon_separation":22.5,"score":null,"score_astronomy":32,"score_weather":null,"transit_alt":50.2,"transit_local":"23:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":5.58,"best_label":"marginal","best_window":"22:00\u201303:35","dark_hours":6.7,"date":"2029-04-25","moon_free_dark_hours":0.0,"moon_illumination":90,"moon_separation":11.3,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":50.2,"transit_local":"23:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.33,"best_label":"marginal","best_window":"22:00\u201303:20","dark_hours":6.64,"date":"2029-04-26","moon_free_dark_hours":0.0,"moon_illumination":96,"moon_separation":13.6,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":50.2,"transit_local":"23:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.08,"best_label":"marginal","best_window":"22:05\u201303:10","dark_hours":6.58,"date":"2029-04-27","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":26.5,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":50.2,"transit_local":"23:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.17,"best_label":"marginal","best_window":"22:05\u201303:15","dark_hours":6.52,"date":"2029-04-28","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":40.8,"score":null,"score_astronomy":34,"score_weather":null,"transit_alt":50.2,"transit_local":"23:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.42,"best_label":"good","best_window":"22:05\u201323:30","dark_hours":6.46,"date":"2029-04-29","moon_free_dark_hours":0.03,"moon_illumination":97,"moon_separation":55.4,"score":null,"score_astronomy":76,"score_weather":null,"transit_alt":50.2,"transit_local":"23:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.42,"best_label":"good","best_window":"22:10\u201301:35","dark_hours":6.41,"date":"2029-04-30","moon_free_dark_hours":1.18,"moon_illumination":91,"moon_separation":69.7,"score":null,"score_astronomy":92,"score_weather":null,"transit_alt":50.2,"transit_local":"23:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.5,"best_label":"good","best_window":"22:10\u201302:40","dark_hours":6.35,"date":"2029-05-01","moon_free_dark_hours":2.13,"moon_illumination":84,"moon_separation":83.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"23:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.58,"best_label":"good","best_window":"22:10\u201302:45","dark_hours":6.29,"date":"2029-05-02","moon_free_dark_hours":2.9,"moon_illumination":75,"moon_separation":97.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"23:10","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.5,"best_label":"good","best_window":"22:15\u201302:45","dark_hours":6.23,"date":"2029-05-03","moon_free_dark_hours":3.53,"moon_illumination":65,"moon_separation":110.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"23:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.5,"best_label":"good","best_window":"22:15\u201302:45","dark_hours":6.17,"date":"2029-05-04","moon_free_dark_hours":4.03,"moon_illumination":55,"moon_separation":122.8,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"23:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.5,"best_label":"good","best_window":"22:15\u201302:45","dark_hours":6.12,"date":"2029-05-05","moon_free_dark_hours":4.47,"moon_illumination":45,"moon_separation":135.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.42,"best_label":"good","best_window":"22:20\u201302:45","dark_hours":6.06,"date":"2029-05-06","moon_free_dark_hours":4.83,"moon_illumination":35,"moon_separation":146.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":4.33,"best_label":"good","best_window":"22:20\u201302:40","dark_hours":6.0,"date":"2029-05-07","moon_free_dark_hours":5.18,"moon_illumination":26,"moon_separation":157.8,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:50","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.25,"best_label":"good","best_window":"22:20\u201302:35","dark_hours":5.95,"date":"2029-05-08","moon_free_dark_hours":5.53,"moon_illumination":19,"moon_separation":167.2,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.08,"best_label":"good","best_window":"22:25\u201302:30","dark_hours":5.89,"date":"2029-05-09","moon_free_dark_hours":5.88,"moon_illumination":12,"moon_separation":169.4,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.08,"best_label":"good","best_window":"22:25\u201302:30","dark_hours":5.83,"date":"2029-05-10","moon_free_dark_hours":5.82,"moon_illumination":6,"moon_separation":161.7,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.0,"best_label":"good","best_window":"22:25\u201302:25","dark_hours":5.78,"date":"2029-05-11","moon_free_dark_hours":5.77,"moon_illumination":3,"moon_separation":151.0,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.83,"best_label":"good","best_window":"22:30\u201302:20","dark_hours":5.72,"date":"2029-05-12","moon_free_dark_hours":5.7,"moon_illumination":0,"moon_separation":139.6,"score":null,"score_astronomy":93,"score_weather":null,"transit_alt":50.2,"transit_local":"22:30","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.75,"best_label":"good","best_window":"22:30\u201302:15","dark_hours":5.67,"date":"2029-05-13","moon_free_dark_hours":5.65,"moon_illumination":0,"moon_separation":127.9,"score":null,"score_astronomy":92,"score_weather":null,"transit_alt":50.2,"transit_local":"22:25","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.67,"best_label":"good","best_window":"22:30\u201302:10","dark_hours":5.62,"date":"2029-05-14","moon_free_dark_hours":5.6,"moon_illumination":2,"moon_separation":116.0,"score":null,"score_astronomy":90,"score_weather":null,"transit_alt":50.2,"transit_local":"22:20","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.58,"best_label":"good","best_window":"22:35\u201302:10","dark_hours":5.56,"date":"2029-05-15","moon_free_dark_hours":5.52,"moon_illumination":5,"moon_separation":103.8,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":50.2,"transit_local":"22:15","verdict":"unknown","weather_source":"none","weekday":"Tue"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2029-04-16","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}}