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Accessing astro TAP servers

by Xilman (Hermit)
on Apr 29, 2020 at 16:38 UTC ( [id://11116225] : perlquestion . print w/replies, xml ) Need Help??

Xilman has asked for the wisdom of the Perl Monks concerning the following question:

Are there any astronomers here who may be able to point me in the right direction of code to access on-line astronomical databases? I am aware of Astro::Catalog:Query, its children and its siblings but I am hitting issues there.

The specific requirement is to be able to download data from the Gaia-DR2 catalogue at which runs a TAP+ service. I have been unable to find anything in CPAN relating to TAP used in this sense (i.e. nothing to do with the Testing Anything Protocol).

A few workarounds have been identified, only one being Perl-based.

The first is to make Vizier queries, either through Astro::Catalog::Query:Vizier or by calling out to the vizquery program distributed as part of the cdstools package. The former modules are elderly and buggy. A couple bugs and their fixes were sent to the maintainers a couple of days ago. A more serious bug, for which a fix is not yet in sight, is that the Vizier query doesn't always return the complete set of records. One particular query which ought to return 315 only gives 55. Other queries are even parsimonious.

Second is to abandon ship and use astropy which has implemented queries to the Gaia database. I've glanced at the code. There is a lot of it and I really would prefer not to have to re-implement it all from scratch in Perl.

Supplementary question: if there really isn't anything implemented, would anyone like to join in to create a package?

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Re: Accessing astro TAP servers
by Xilman (Hermit) on May 01, 2020 at 09:51 UTC

    The author of Astro::Catalog::Query:Vizier now has a preliminary fix to the module. He has mailed it to me.