python-skyfield: 404 error when attempting to load Hipparcos data

When I do load.open(hipparcos.URL) on a fresh install of skyfield, I’m getting this error:

OSError: cannot download http://cdsarc.u-strasbg.fr/ftp/cats/I/239/hip_main.dat.gz because HTTP Error 404: Not Found

About this issue

  • Original URL
  • State: closed
  • Created 4 years ago
  • Comments: 16 (10 by maintainers)

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I am resetting the title of this issue back to its original value “404 error when attempting to load Hipparcos data” since the original issue was the change in the database’s URL. Now that everyone can get to Hipparcos again, I am (a) not aware of any users blocked waiting for Skyfield to learn how to parse Vizier table downloads, and (b) I am not sure that we would want to make that a Skyfield-only feature. It might make more sense for Python to have a 3rd party library that knew how to read the Vizier headers and NumPy-parse the lines of data that followed — for example, imagine something like:

https://astroquery.readthedocs.io/en/latest/vizier/vizier.html

— but able to return a plain Pandas dataframe instead of requiring a full AstroPy install. Then all kinds of tools, Skyfield included, could benefit from Vizier data, without each having to internally implement the same parsing logic.

I will be happy to consider counter-arguments against either of those premises, but at the moment they seem strong enough to me that I’m going to close this issue for now, since the original issue is long resolved.

If anyone who hadn’t spoken up yet is indeed blocked on the lack of a general mechanism in Skyfield for Vizier table downloads, simply reply here with further information about which tables you need, and we can discuss whether the work is in scope for Skyfield contributors. Thanks!