Skyfield astronomy library

Skyfield version 1.47 has just been released, with much faster rising, setting, and transit routines — that also don’t have any problem with locations in the high Arctic and Antarctic! #risings-and-settings" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/alman…

Also, there's now an example in the Skyfield docs showing how to compute the rates at which a body’s position is changing—either as rates of change for RA and dec, or for altitude and azimuth: #at-what-rate-is-a-target-moving-across-the-sky" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/examp…

Skyfield 1.44 has been released! There is now an easier way to build distance and velocity objects, the Hipparcos URL has been updated, and the internal ∆T table has been updated. #v1-44-2022-september-12" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/insta…

Skyfield 1.39 is out! The Angle.dstr() and Angle.hstr() methods now accept a “format=” argument that lets callers override Skyfield’s default angle formatting and supply their own. For details, read: #formatting-angles" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/api-u…

Skyfield 1.38 was released this weekend! The old ∆T tables have been replaced with splines from the latest research by Stephenson, Morrison, Hohenkerk, and Zawilski: astro.ukho.gov.uk/nao/lvm/ So, alt-az calculations for ancient and medieval dates should now be more accurate!

Skyfield 1.34 adds explicit support for the ITRS reference frame, polar motion, Sidereal Time, and the exact phase of the Moon. Read all the details here: #v1-34-2020-december-10" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/insta…

Skyfield 1.32 is out — featuring new routines for finding lunar eclipses, and for finding when an object transits your meridian overhead! #v1-32-2020-november-16" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/insta…

Note that all recent Skyfield versions use the default: load.timescale(builtin=True) — in which case your program will not attempt a live download either way! Details: #ut1-and-downloading-iers-data" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/time.… github.com/skyfielders/py… Thanks to Dan Small for alerting us to the deadline. 2/2

Skyfield 1.31 was released earlier this week, with a big change: Ahead of NASA’s shutdown of an FTP site at the end of this month, Skyfield now downloads leap second and ∆T data from the IERS instead. Happily, this also increases the data’s accuracy! 1/2

The sgp4 library that Skyfield uses for Earth satellites has just released 2.13, which now sets both `epochyr` and `epochdays` when you set up a satellite by hand with sgp4init(). Result? You can now successfully save such a satellite as a TLE! pypi.org/project/sgp4/

Skyfield 1.27 is out! Highlights include a time attribute “.J” that returns floating point Julian years, and a slate of “strftime” methods for the timescales TAI, TT, TDB, and UT1. #september-15" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/insta…

Skyfield 1.26 no longer decides your timescale files are out of date and risks a network failure by trying to download new ones! Instead, you are given to the tools to check whether they are up-to-date: #downloading-new-timescale-files" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/time.…

We released a new Skyfield version 1.10 last week — with a fix for the change in how the Naval Observatory’s essential “deltat.preds” file is formatted. If you see an error, simply upgrade! #changelog" target="_blank" rel="nofollow noopener">rhodesmill.org/skyfield/insta…