{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":0.33,"best_label":"marginal","best_window":"05:15\u201305:35","dark_hours":9.91,"date":"2026-02-23","moon_free_dark_hours":4.28,"moon_illumination":43,"moon_separation":100.3,"score":5,"score_astronomy":17,"score_weather":31,"transit_alt":71.1,"transit_local":"10:05","verdict":"poor","weather_source":"history","weekday":"Mon"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":9.87,"date":"2026-02-24","moon_free_dark_hours":3.0,"moon_illumination":55,"moon_separation":110.0,"score":1,"score_astronomy":17,"score_weather":4,"transit_alt":71.1,"transit_local":"10:00","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":9.83,"date":"2026-02-25","moon_free_dark_hours":1.87,"moon_illumination":66,"moon_separation":118.9,"score":0,"score_astronomy":19,"score_weather":0,"transit_alt":71.1,"transit_local":"10:00","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.92,"best_label":"marginal","best_window":"04:35\u201305:30","dark_hours":9.78,"date":"2026-02-26","moon_free_dark_hours":0.92,"moon_illumination":76,"moon_separation":126.6,"score":11,"score_astronomy":19,"score_weather":57,"transit_alt":71.1,"transit_local":"09:55","verdict":"poor","weather_source":"history","weekday":"Thu"},{"best_hours":0.42,"best_label":"good","best_window":"05:05\u201305:30","dark_hours":9.74,"date":"2026-02-27","moon_free_dark_hours":0.13,"moon_illumination":85,"moon_separation":132.3,"score":19,"score_astronomy":20,"score_weather":94,"transit_alt":71.1,"transit_local":"09:50","verdict":"poor","weather_source":"history","weekday":"Fri"},{"best_hours":0.5,"best_label":"good","best_window":"04:55\u201305:25","dark_hours":9.69,"date":"2026-02-28","moon_free_dark_hours":0.0,"moon_illumination":92,"moon_separation":135.1,"score":17,"score_astronomy":17,"score_weather":100,"transit_alt":71.1,"transit_local":"09:45","verdict":"poor","weather_source":"history","weekday":"Sat"},{"best_hours":0.08,"best_label":"good","best_window":"04:55\u201305:00","dark_hours":9.65,"date":"2026-03-01","moon_free_dark_hours":0.0,"moon_illumination":97,"moon_separation":134.7,"score":8,"score_astronomy":18,"score_weather":47,"transit_alt":71.1,"transit_local":"09:40","verdict":"poor","weather_source":"history","weekday":"Sun"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":9.6,"date":"2026-03-02","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":131.1,"score":0,"score_astronomy":18,"score_weather":0,"transit_alt":71.1,"transit_local":"09:40","verdict":"unusable","weather_source":"history","weekday":"Mon"},{"best_hours":0.58,"best_label":"good","best_window":"04:45\u201305:20","dark_hours":9.56,"date":"2026-03-03","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":125.2,"score":18,"score_astronomy":18,"score_weather":99,"transit_alt":71.1,"transit_local":"09:35","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":9.51,"date":"2026-03-04","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":117.9,"score":0,"score_astronomy":19,"score_weather":0,"transit_alt":71.1,"transit_local":"09:30","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.67,"best_label":"good","best_window":"04:40\u201305:20","dark_hours":9.46,"date":"2026-03-05","moon_free_dark_hours":0.88,"moon_illumination":94,"moon_separation":109.7,"score":18,"score_astronomy":18,"score_weather":100,"transit_alt":71.1,"transit_local":"09:25","verdict":"poor","weather_source":"history","weekday":"Thu"},{"best_hours":0.92,"best_label":"marginal","best_window":"04:05\u201305:00","dark_hours":9.41,"date":"2026-03-06","moon_free_dark_hours":1.97,"moon_illumination":88,"moon_separation":101.2,"score":11,"score_astronomy":17,"score_weather":66,"transit_alt":71.1,"transit_local":"09:25","verdict":"poor","weather_source":"history","weekday":"Fri"},{"best_hours":0.33,"best_label":"good","best_window":"04:40\u201305:00","dark_hours":9.37,"date":"2026-03-07","moon_free_dark_hours":3.03,"moon_illumination":81,"moon_separation":92.6,"score":14,"score_astronomy":17,"score_weather":82,"transit_alt":71.1,"transit_local":"09:20","verdict":"poor","weather_source":"history","weekday":"Sat"},{"best_hours":0.25,"best_label":"marginal","best_window":"05:00\u201305:15","dark_hours":9.32,"date":"2026-03-08","moon_free_dark_hours":4.12,"moon_illumination":72,"moon_separation":84.0,"score":5,"score_astronomy":17,"score_weather":32,"transit_alt":71.1,"transit_local":"09:15","verdict":"poor","weather_source":"history","weekday":"Sun"},{"best_hours":0.25,"best_label":"good","best_window":"04:45\u201305:00","dark_hours":9.27,"date":"2026-03-09","moon_free_dark_hours":5.15,"moon_illumination":64,"moon_separation":75.7,"score":15,"score_astronomy":17,"score_weather":89,"transit_alt":71.1,"transit_local":"09:10","verdict":"poor","weather_source":"history","weekday":"Mon"},{"best_hours":0.75,"best_label":"good","best_window":"04:25\u201305:10","dark_hours":9.22,"date":"2026-03-10","moon_free_dark_hours":6.13,"moon_illumination":54,"moon_separation":67.8,"score":19,"score_astronomy":19,"score_weather":100,"transit_alt":71.1,"transit_local":"09:05","verdict":"poor","weather_source":"history","weekday":"Tue"},{"best_hours":0.75,"best_label":"marginal","best_window":"04:15\u201305:00","dark_hours":9.17,"date":"2026-03-11","moon_free_dark_hours":7.02,"moon_illumination":45,"moon_separation":60.4,"score":11,"score_astronomy":21,"score_weather":52,"transit_alt":71.1,"transit_local":"09:05","verdict":"poor","weather_source":"history","weekday":"Wed"},{"best_hours":0.92,"best_label":"good","best_window":"04:10\u201305:05","dark_hours":9.13,"date":"2026-03-12","moon_free_dark_hours":7.78,"moon_illumination":36,"moon_separation":53.9,"score":23,"score_astronomy":23,"score_weather":99,"transit_alt":71.1,"transit_local":"09:00","verdict":"poor","weather_source":"history","weekday":"Thu"},{"best_hours":1.17,"best_label":"good","best_window":"03:55\u201305:05","dark_hours":9.08,"date":"2026-03-13","moon_free_dark_hours":8.42,"moon_illumination":27,"moon_separation":48.7,"score":28,"score_astronomy":28,"score_weather":100,"transit_alt":71.1,"transit_local":"08:55","verdict":"poor","weather_source":"history","weekday":"Fri"},{"best_hours":1.17,"best_label":"good","best_window":"03:55\u201305:05","dark_hours":9.03,"date":"2026-03-14","moon_free_dark_hours":8.92,"moon_illumination":18,"moon_separation":45.4,"score":30,"score_astronomy":31,"score_weather":95,"transit_alt":71.1,"transit_local":"08:50","verdict":"poor","weather_source":"history","weekday":"Sat"},{"best_hours":1.25,"best_label":"good","best_window":"03:45\u201305:00","dark_hours":8.98,"date":"2026-03-15","moon_free_dark_hours":8.95,"moon_illumination":11,"moon_separation":44.7,"score":32,"score_astronomy":32,"score_weather":100,"transit_alt":71.1,"transit_local":"08:45","verdict":"poor","weather_source":"history","weekday":"Sun"},{"best_hours":1.0,"best_label":"good","best_window":"04:00\u201305:00","dark_hours":8.93,"date":"2026-03-16","moon_free_dark_hours":8.92,"moon_illumination":5,"moon_separation":47.0,"score":24,"score_astronomy":33,"score_weather":72,"transit_alt":71.1,"transit_local":"08:45","verdict":"poor","weather_source":"history","weekday":"Mon"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.88,"date":"2026-03-17","moon_free_dark_hours":8.87,"moon_illumination":2,"moon_separation":51.9,"score":0,"score_astronomy":35,"score_weather":0,"transit_alt":71.1,"transit_local":"08:40","verdict":"unusable","weather_source":"history","weekday":"Tue"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.82,"date":"2026-03-18","moon_free_dark_hours":8.82,"moon_illumination":0,"moon_separation":59.0,"score":0,"score_astronomy":35,"score_weather":0,"transit_alt":71.1,"transit_local":"08:35","verdict":"unusable","weather_source":"history","weekday":"Wed"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.77,"date":"2026-03-19","moon_free_dark_hours":8.75,"moon_illumination":1,"moon_separation":67.7,"score":0,"score_astronomy":36,"score_weather":0,"transit_alt":71.1,"transit_local":"08:30","verdict":"unusable","weather_source":"history","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.72,"date":"2026-03-20","moon_free_dark_hours":8.4,"moon_illumination":5,"moon_separation":77.4,"score":0,"score_astronomy":36,"score_weather":0,"transit_alt":71.1,"transit_local":"08:30","verdict":"unusable","weather_source":"history","weekday":"Fri"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.67,"date":"2026-03-21","moon_free_dark_hours":7.07,"moon_illumination":11,"moon_separation":87.5,"score":0,"score_astronomy":37,"score_weather":0,"transit_alt":71.1,"transit_local":"08:25","verdict":"unusable","weather_source":"history","weekday":"Sat"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.62,"date":"2026-03-22","moon_free_dark_hours":5.73,"moon_illumination":19,"moon_separation":97.8,"score":0,"score_astronomy":39,"score_weather":0,"transit_alt":71.1,"transit_local":"08:20","verdict":"unusable","weather_source":"history","weekday":"Sun"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.57,"date":"2026-03-23","moon_free_dark_hours":4.42,"moon_illumination":29,"moon_separation":107.8,"score":0,"score_astronomy":38,"score_weather":0,"transit_alt":71.1,"transit_local":"08:15","verdict":"unusable","weather_source":"history","weekday":"Mon"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":8.51,"date":"2026-03-24","moon_free_dark_hours":3.22,"moon_illumination":40,"moon_separation":117.0,"score":0,"score_astronomy":40,"score_weather":0,"transit_alt":71.1,"transit_local":"08:10","verdict":"unusable","weather_source":"history","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":"2026-02-23","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}}
