Comment 29 for bug 1124221

Hello Alexander,

Beside the proper motion there is of course also for some 9 years the
precession of the equator to get from J1991.25 to J2000.0, was that
included? Thanks.

All the best,

Victor

On 1 March 2013 16:41, Alexander Wolf <email address hidden> wrote:

> Tycho 2 supplement contains stars for J2000.0 and J 1991.25 epochs. I'm
> download original Hipparcos and Tycho 2, Hipparcos for J2000.0 from
> VizieR. Next step: write small converter on Perl for merge J2000.0
> coordinates to original Hipparcos catalog + disable changeEpoch() and
> add "fix" for Hipparcos stars from Tycho supplement part.
>
> Diff:
> http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/5865
>
> ** Changed in: stellarium
> Status: In Progress => Fix Committed
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1124221
>
> Title:
> Stellarium uses Hypparcos star coordinates from J2000.0 instead of
> J1991.25
>
> Status in Stellarium:
> Fix Committed
>
> Bug description:
> It looks that the RA/DE(J2000) on date/time 2000/1/1 12:00 (aka
> J2000.0) in
> Stellarium is precisely the value that is defined in Hipparcos (which is
> defined at J1991.25).
> Example: in
> http://www.rssd.esa.int/index.php?project=HIPPARCOS&page=multisearch2 ,
> Sirius is in Hipparcos catalogue (being J1991.25) at:
> H| 32349| |06 45 09.25|-16 42 47.3
>
> If I look at Stellarium on Date/time 1991/1/1 18:00 GMT (J1991.25) I get:
> RA/DE (J2000): 6h45m9.6s/-16°42'35.8"
>
> And on date/time 2000/1/1/ 12:00 GMT (J2000.0)I get in Stellarium:
> RA/DE (J2000): 6h45m9.3s/-16°42'47.3"
>
> I am using 0.12.0 and 0.12.1, Windows XP Pro, SP3,
>
> See also: <email address hidden>
>
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