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UCAC5 - Any users?

Posted: 09 Aug 2020, 22:41
by merlin66
I use UCAC4 but just noticed that UCAC5 was issued back in 2017.
It's not even mentioned on the UCAC website!
https://www.usno.navy.mil/USNO/astromet ... -prod/ucac
Has anyone tried it yet??

Re: UCAC5 - Any users?

Posted: 12 Aug 2020, 11:41
by fabdev
Well, the UCAC4 was already very good, with its precision better than 0.07 arcseconds.

The version available of the UCAC5:
ftp://cdsarc.u-strasbg.fr/pub/cats/I/340/UCAC5/u5z/

contains the same 107 million stars, the difference is just a further precision thanks to re-reduction with the Gaia data, as written in point 1 (Overview and Goals) here:

http://tdc-www.harvard.edu/software/catalogs/ucac5.html

There's also another version (point 2) which contains more stars, 500 millions, but it's available only on request.

The binary format of the UCAC5 is different by the way, so it cannot be read by Astroart. I will take a look at it in the future.
Thanks, Fabio.