The ones used by underluckystars.com and thenightsky.com

I have found several but I am having difficulty finding a working updated version, has anyone come across this API, or know where I can find it?

  • $\begingroup$ What do you exactly want: to find a beautiful star map or an accurate star map? $\endgroup$
    – User123
    Aug 1, 2019 at 10:03
  • $\begingroup$ I want a webapp that creates accurate starmaps like those sites $\endgroup$
    – Akalife
    Aug 2, 2019 at 16:22
  • $\begingroup$ you can now use astronomyapi.com api to do this. it's free $\endgroup$
    – astroanu
    Nov 20, 2020 at 6:20

1 Answer 1


Those vendors don't need an API, and neither do you. What their "how it works" pages do talk about are star catalogs and map projections.

The Bright Star Catalog has about 9000 stars down to magnitude 6, as faint as most people can see in a dark sky without optical aid. The Hipparcos catalog has about 100k stars down to magnitude 9 or 10. The key data for a star map are equatorial coordinates (right ascension, declination) and V-band apparent magnitude. For an all-sky map, which typically uses a stereographic projection to plot everything within 90° of the zenith (RA = sidereal time, Dec = geographic latitude), transformation to horizontal coordinates may be a useful intermediate step.

If you like working in Python, either Skyfield or Astropy/Astroquery can help you retrieve and process the data but will not plot the map.

  • $\begingroup$ Thank you very much Mike, really appreciate the help! $\endgroup$
    – Akalife
    Aug 2, 2019 at 16:38
  • $\begingroup$ I am also looking for this info. The abive answer sounds really smart bust does not offer and answer. It simply tells the person to learn PYTHON. Which is not how these are done. They are tied to an API. We are both wondering WHICH API and the links to them. $\endgroup$ May 19, 2020 at 17:53
  • $\begingroup$ @OldF'nSchool I looked for a web API but didn't find one. Any programming language will do. $\endgroup$
    – Mike G
    May 19, 2020 at 21:31
  • $\begingroup$ @OldF'nSchool at some point a question ceases to be about Astronomy at which point it no longer belongs on this site. For example How (the heck) does Astrometry.net work? was on topic because it asks about the underlying astronomical image processing algorithm rather than the API. If the question is about web apps then rather than complaining here, perhaps a similar but non-identical question can be posted in Web Applications SE focusing on how those applications work. $\endgroup$
    – uhoh
    Oct 2, 2020 at 1:07

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