{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":0.17,"best_label":"good","best_window":"05:30\u201305:40","dark_hours":10.18,"date":"2027-02-17","moon_free_dark_hours":0.18,"moon_illumination":87,"moon_separation":130.8,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":71.1,"transit_local":"10:30","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.08,"best_label":"good","best_window":"05:35\u201305:40","dark_hours":10.13,"date":"2027-02-18","moon_free_dark_hours":0.0,"moon_illumination":94,"moon_separation":135.7,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":71.1,"transit_local":"10:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.17,"best_label":"good","best_window":"05:30\u201305:40","dark_hours":10.09,"date":"2027-02-19","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":136.9,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":71.1,"transit_local":"10:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.25,"best_label":"good","best_window":"05:25\u201305:40","dark_hours":10.05,"date":"2027-02-20","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":134.0,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":71.1,"transit_local":"10:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.17,"best_label":"good","best_window":"05:25\u201305:35","dark_hours":10.01,"date":"2027-02-21","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":127.9,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":71.1,"transit_local":"10:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.25,"best_label":"good","best_window":"05:20\u201305:35","dark_hours":9.97,"date":"2027-02-22","moon_free_dark_hours":0.58,"moon_illumination":95,"moon_separation":119.9,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":71.1,"transit_local":"10:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.25,"best_label":"good","best_window":"05:20\u201305:35","dark_hours":9.92,"date":"2027-02-23","moon_free_dark_hours":1.78,"moon_illumination":89,"moon_separation":110.8,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":71.1,"transit_local":"10:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.25,"best_label":"good","best_window":"05:20\u201305:35","dark_hours":9.88,"date":"2027-02-24","moon_free_dark_hours":2.97,"moon_illumination":81,"moon_separation":101.3,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":71.1,"transit_local":"10:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.25,"best_label":"good","best_window":"05:15\u201305:30","dark_hours":9.84,"date":"2027-02-25","moon_free_dark_hours":4.12,"moon_illumination":72,"moon_separation":91.9,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":71.1,"transit_local":"10:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.33,"best_label":"good","best_window":"05:10\u201305:30","dark_hours":9.79,"date":"2027-02-26","moon_free_dark_hours":5.23,"moon_illumination":62,"moon_separation":82.6,"score":null,"score_astronomy":13,"score_weather":null,"transit_alt":71.1,"transit_local":"09:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.42,"best_label":"good","best_window":"05:05\u201305:30","dark_hours":9.75,"date":"2027-02-27","moon_free_dark_hours":6.28,"moon_illumination":53,"moon_separation":73.8,"score":null,"score_astronomy":14,"score_weather":null,"transit_alt":71.1,"transit_local":"09:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.42,"best_label":"good","best_window":"05:00\u201305:25","dark_hours":9.7,"date":"2027-02-28","moon_free_dark_hours":7.22,"moon_illumination":43,"moon_separation":65.6,"score":null,"score_astronomy":15,"score_weather":null,"transit_alt":71.1,"transit_local":"09:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.5,"best_label":"good","best_window":"04:55\u201305:25","dark_hours":9.66,"date":"2027-03-01","moon_free_dark_hours":8.03,"moon_illumination":34,"moon_separation":58.1,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":71.1,"transit_local":"09:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.67,"best_label":"good","best_window":"04:45\u201305:25","dark_hours":9.61,"date":"2027-03-02","moon_free_dark_hours":8.73,"moon_illumination":25,"moon_separation":51.6,"score":null,"score_astronomy":19,"score_weather":null,"transit_alt":71.1,"transit_local":"09:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.75,"best_label":"good","best_window":"04:35\u201305:20","dark_hours":9.57,"date":"2027-03-03","moon_free_dark_hours":9.28,"moon_illumination":18,"moon_separation":46.6,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":71.1,"transit_local":"09:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.83,"best_label":"good","best_window":"04:30\u201305:20","dark_hours":9.52,"date":"2027-03-04","moon_free_dark_hours":9.52,"moon_illumination":11,"moon_separation":43.6,"score":null,"score_astronomy":24,"score_weather":null,"transit_alt":71.1,"transit_local":"09:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.92,"best_label":"good","best_window":"04:25\u201305:20","dark_hours":9.47,"date":"2027-03-05","moon_free_dark_hours":9.47,"moon_illumination":6,"moon_separation":43.2,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":71.1,"transit_local":"09:30","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.83,"best_label":"good","best_window":"04:25\u201305:15","dark_hours":9.43,"date":"2027-03-06","moon_free_dark_hours":9.4,"moon_illumination":2,"moon_separation":45.4,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":71.1,"transit_local":"09:25","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.92,"best_label":"good","best_window":"04:20\u201305:15","dark_hours":9.38,"date":"2027-03-07","moon_free_dark_hours":9.37,"moon_illumination":0,"moon_separation":50.0,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":71.1,"transit_local":"09:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.0,"best_label":"good","best_window":"04:15\u201305:15","dark_hours":9.33,"date":"2027-03-08","moon_free_dark_hours":9.32,"moon_illumination":0,"moon_separation":56.5,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":71.1,"transit_local":"09:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.0,"best_label":"good","best_window":"04:10\u201305:10","dark_hours":9.28,"date":"2027-03-09","moon_free_dark_hours":9.27,"moon_illumination":3,"moon_separation":64.4,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":71.1,"transit_local":"09:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.08,"best_label":"good","best_window":"04:05\u201305:10","dark_hours":9.23,"date":"2027-03-10","moon_free_dark_hours":8.42,"moon_illumination":7,"moon_separation":73.3,"score":null,"score_astronomy":29,"score_weather":null,"transit_alt":71.1,"transit_local":"09:10","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.08,"best_label":"good","best_window":"04:05\u201305:10","dark_hours":9.19,"date":"2027-03-11","moon_free_dark_hours":7.22,"moon_illumination":13,"moon_separation":82.7,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":71.1,"transit_local":"09:05","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.08,"best_label":"good","best_window":"04:00\u201305:05","dark_hours":9.14,"date":"2027-03-12","moon_free_dark_hours":5.98,"moon_illumination":21,"moon_separation":92.5,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":71.1,"transit_local":"09:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.17,"best_label":"good","best_window":"03:55\u201305:05","dark_hours":9.09,"date":"2027-03-13","moon_free_dark_hours":4.75,"moon_illumination":31,"moon_separation":102.4,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":71.1,"transit_local":"08:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.25,"best_label":"good","best_window":"03:50\u201305:05","dark_hours":9.04,"date":"2027-03-14","moon_free_dark_hours":3.57,"moon_illumination":42,"moon_separation":112.0,"score":null,"score_astronomy":32,"score_weather":null,"transit_alt":71.1,"transit_local":"08:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.25,"best_label":"good","best_window":"03:45\u201305:00","dark_hours":8.99,"date":"2027-03-15","moon_free_dark_hours":2.5,"moon_illumination":53,"moon_separation":121.0,"score":null,"score_astronomy":32,"score_weather":null,"transit_alt":71.1,"transit_local":"08:50","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.25,"best_label":"good","best_window":"03:45\u201305:00","dark_hours":8.94,"date":"2027-03-16","moon_free_dark_hours":1.58,"moon_illumination":64,"moon_separation":128.8,"score":null,"score_astronomy":34,"score_weather":null,"transit_alt":71.1,"transit_local":"08:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.25,"best_label":"good","best_window":"03:45\u201305:00","dark_hours":8.89,"date":"2027-03-17","moon_free_dark_hours":0.83,"moon_illumination":75,"moon_separation":134.5,"score":null,"score_astronomy":34,"score_weather":null,"transit_alt":71.1,"transit_local":"08:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.25,"best_label":"good","best_window":"03:40\u201304:55","dark_hours":8.84,"date":"2027-03-18","moon_free_dark_hours":0.23,"moon_illumination":84,"moon_separation":137.0,"score":null,"score_astronomy":33,"score_weather":null,"transit_alt":71.1,"transit_local":"08:35","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":"2027-02-17","target":{"dec":22.71085365,"name":"HD 189733","ra":300.18213726,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=HD%20189733","source":"sesame","spectral_type":"K2V","type":"BY*","type_text":"BY Draconis variable \u2014 a spotted, rotating star","vmag":7.648}}