KeptStars research · evening
Calculated 2026-11-09.

Install numpy and skyfield==1.54. Download JPL de421.bsp using the Skyfield documentation link in method.json. Run python calculate.py --ephemeris de421.bsp. All positions omit atmospheric refraction. Independent numerical comparisons are in independent-altitudes.json; they are audit evidence, not an input to the calculation.

DATA LICENCE: CC BY 4.0
https://creativecommons.org/licenses/by/4.0/
KeptStars Team; Derived calculations and charts are licensed under CC BY 4.0.

Public study: https://keptstars.com/blog/evening-stargazing-calendar-2027
Method and limitations: method.json
