{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":1.58,"best_label":"good","best_window":"03:10\u201304:45","dark_hours":8.47,"date":"2039-03-25","moon_free_dark_hours":8.45,"moon_illumination":2,"moon_separation":78.5,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":71.1,"transit_local":"08:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.58,"best_label":"good","best_window":"04:05\u201305:40","dark_hours":8.42,"date":"2039-03-26","moon_free_dark_hours":8.33,"moon_illumination":5,"moon_separation":87.0,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":71.1,"transit_local":"09:05","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.67,"best_label":"good","best_window":"04:00\u201305:40","dark_hours":8.36,"date":"2039-03-27","moon_free_dark_hours":7.28,"moon_illumination":10,"moon_separation":95.4,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":71.1,"transit_local":"09:00","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.67,"best_label":"good","best_window":"03:55\u201305:35","dark_hours":8.31,"date":"2039-03-28","moon_free_dark_hours":6.25,"moon_illumination":16,"moon_separation":103.6,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":71.1,"transit_local":"08:55","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.75,"best_label":"good","best_window":"03:50\u201305:35","dark_hours":8.25,"date":"2039-03-29","moon_free_dark_hours":5.23,"moon_illumination":23,"moon_separation":111.4,"score":null,"score_astronomy":44,"score_weather":null,"transit_alt":71.1,"transit_local":"08:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.75,"best_label":"good","best_window":"03:50\u201305:35","dark_hours":8.2,"date":"2039-03-30","moon_free_dark_hours":4.22,"moon_illumination":32,"moon_separation":118.7,"score":null,"score_astronomy":45,"score_weather":null,"transit_alt":71.1,"transit_local":"08:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.75,"best_label":"good","best_window":"03:45\u201305:30","dark_hours":8.15,"date":"2039-03-31","moon_free_dark_hours":3.25,"moon_illumination":41,"moon_separation":125.1,"score":null,"score_astronomy":45,"score_weather":null,"transit_alt":71.1,"transit_local":"08:45","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.83,"best_label":"good","best_window":"03:40\u201305:30","dark_hours":8.09,"date":"2039-04-01","moon_free_dark_hours":2.33,"moon_illumination":50,"moon_separation":130.2,"score":null,"score_astronomy":46,"score_weather":null,"transit_alt":71.1,"transit_local":"08:40","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.83,"best_label":"good","best_window":"03:40\u201305:30","dark_hours":8.04,"date":"2039-04-02","moon_free_dark_hours":1.52,"moon_illumination":60,"moon_separation":133.5,"score":null,"score_astronomy":47,"score_weather":null,"transit_alt":71.1,"transit_local":"08:40","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.75,"best_label":"good","best_window":"03:40\u201305:25","dark_hours":7.98,"date":"2039-04-03","moon_free_dark_hours":0.77,"moon_illumination":70,"moon_separation":134.4,"score":null,"score_astronomy":46,"score_weather":null,"transit_alt":71.1,"transit_local":"08:35","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.83,"best_label":"good","best_window":"03:35\u201305:25","dark_hours":7.93,"date":"2039-04-04","moon_free_dark_hours":0.12,"moon_illumination":79,"moon_separation":132.5,"score":null,"score_astronomy":46,"score_weather":null,"transit_alt":71.1,"transit_local":"08:30","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.75,"best_label":"good","best_window":"03:35\u201305:20","dark_hours":7.87,"date":"2039-04-05","moon_free_dark_hours":0.0,"moon_illumination":87,"moon_separation":128.0,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":71.1,"transit_local":"08:25","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.83,"best_label":"good","best_window":"03:30\u201305:20","dark_hours":7.81,"date":"2039-04-06","moon_free_dark_hours":0.0,"moon_illumination":93,"moon_separation":121.2,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":71.1,"transit_local":"08:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.83,"best_label":"good","best_window":"03:30\u201305:20","dark_hours":7.76,"date":"2039-04-07","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":112.7,"score":null,"score_astronomy":38,"score_weather":null,"transit_alt":71.1,"transit_local":"08:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.67,"best_label":"good","best_window":"03:35\u201305:15","dark_hours":7.7,"date":"2039-04-08","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":103.1,"score":null,"score_astronomy":33,"score_weather":null,"transit_alt":71.1,"transit_local":"08:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.33,"best_label":"good","best_window":"03:55\u201305:15","dark_hours":7.64,"date":"2039-04-09","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":92.8,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":71.1,"transit_local":"08:10","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.75,"best_label":"good","best_window":"04:25\u201305:10","dark_hours":7.59,"date":"2039-04-10","moon_free_dark_hours":0.22,"moon_illumination":95,"moon_separation":82.4,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":71.1,"transit_local":"08:05","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.5,"best_label":"good","best_window":"04:40\u201305:10","dark_hours":7.53,"date":"2039-04-11","moon_free_dark_hours":1.5,"moon_illumination":89,"moon_separation":72.3,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":71.1,"transit_local":"08:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.67,"best_label":"good","best_window":"04:30\u201305:10","dark_hours":7.47,"date":"2039-04-12","moon_free_dark_hours":2.75,"moon_illumination":80,"moon_separation":63.0,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":71.1,"transit_local":"08:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.33,"best_label":"good","best_window":"03:45\u201305:05","dark_hours":7.42,"date":"2039-04-13","moon_free_dark_hours":3.92,"moon_illumination":70,"moon_separation":55.1,"score":null,"score_astronomy":28,"score_weather":null,"transit_alt":71.1,"transit_local":"07:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.92,"best_label":"good","best_window":"03:10\u201305:05","dark_hours":7.36,"date":"2039-04-14","moon_free_dark_hours":4.93,"moon_illumination":59,"moon_separation":49.2,"score":null,"score_astronomy":34,"score_weather":null,"transit_alt":71.1,"transit_local":"07:50","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.25,"best_label":"good","best_window":"02:45\u201305:00","dark_hours":7.3,"date":"2039-04-15","moon_free_dark_hours":5.78,"moon_illumination":48,"moon_separation":46.1,"score":null,"score_astronomy":44,"score_weather":null,"transit_alt":71.1,"transit_local":"07:45","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.33,"best_label":"good","best_window":"02:40\u201305:00","dark_hours":7.24,"date":"2039-04-16","moon_free_dark_hours":6.47,"moon_illumination":37,"moon_separation":46.0,"score":null,"score_astronomy":52,"score_weather":null,"transit_alt":71.1,"transit_local":"07:45","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.42,"best_label":"good","best_window":"02:35\u201305:00","dark_hours":7.19,"date":"2039-04-17","moon_free_dark_hours":7.03,"moon_illumination":27,"moon_separation":48.8,"score":null,"score_astronomy":59,"score_weather":null,"transit_alt":71.1,"transit_local":"07:40","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.33,"best_label":"good","best_window":"02:35\u201304:55","dark_hours":7.13,"date":"2039-04-18","moon_free_dark_hours":7.1,"moon_illumination":19,"moon_separation":53.9,"score":null,"score_astronomy":61,"score_weather":null,"transit_alt":71.1,"transit_local":"07:35","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.42,"best_label":"good","best_window":"02:30\u201304:55","dark_hours":7.07,"date":"2039-04-19","moon_free_dark_hours":7.05,"moon_illumination":12,"moon_separation":60.5,"score":null,"score_astronomy":62,"score_weather":null,"transit_alt":71.1,"transit_local":"07:30","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.5,"best_label":"good","best_window":"02:25\u201304:55","dark_hours":7.01,"date":"2039-04-20","moon_free_dark_hours":7.0,"moon_illumination":6,"moon_separation":68.1,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":71.1,"transit_local":"07:25","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.5,"best_label":"good","best_window":"02:20\u201304:50","dark_hours":6.95,"date":"2039-04-21","moon_free_dark_hours":6.95,"moon_illumination":2,"moon_separation":76.2,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":71.1,"transit_local":"07:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":2.5,"best_label":"good","best_window":"02:20\u201304:50","dark_hours":6.9,"date":"2039-04-22","moon_free_dark_hours":6.88,"moon_illumination":0,"moon_separation":84.5,"score":null,"score_astronomy":65,"score_weather":null,"transit_alt":71.1,"transit_local":"07:20","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.5,"best_label":"good","best_window":"02:15\u201304:45","dark_hours":6.84,"date":"2039-04-23","moon_free_dark_hours":6.83,"moon_illumination":0,"moon_separation":92.9,"score":null,"score_astronomy":66,"score_weather":null,"transit_alt":71.1,"transit_local":"07:15","verdict":"unknown","weather_source":"none","weekday":"Sat"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2039-03-25","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}}