Comment 2 for bug 1124221

Hello Alexander,

So here is all the data:
Stellarium: 2000/1/1 12:00 (J2000.0)
Sirius (α CMa) - HIP 32349
Type: star
Magnitude: -1.45 (extincted to: 6.95. B-V: 0.00)
Absolute Magnitude: 1.44
RA/DE (J2000): 6h45m9.3s/-16°42'47.3"
RA/DE (of date): 6h45m9s/-16°42'47"
Galactic longitude/latitude (J2000): -132°46'18.6"/-8°53'16.1"
Hour angle/DE: 15h10m22s/-16°42'47" (geometric)
Hour angle/DE: 15h10m22s/-16°42'47" (apparent)
Az/Alt: +49°46'58"/-60°41'57" (geometric)
Az/Alt: +49°46'58"/-60°41'57" (apparent)
Spectral Type: A0m...
Distance: 8.60 Light Years
Parallax: 0.37921"

Stellarium: 1991/1/1 18:00 (J1911.25)
Sirius (α CMa) - HIP 32349
Type: star
Magnitude: -1.45 (extincted to: 6.95. B-V: 0.00)
Absolute Magnitude: 1.44
RA/DE (J2000): 6h45m9.3s/-16°42'47.3"
RA/DE (of date): 6h45m9s/-16°42'47"
Galactic longitude/latitude (J2000): -132°46'18.6"/-8°53'16.1"
Hour angle/DE: 15h10m22s/-16°42'47" (geometric)
Hour angle/DE: 15h10m22s/-16°42'47" (apparent)
Az/Alt: +49°46'58"/-60°41'57" (geometric)
Az/Alt: +49°46'58"/-60°41'57" (apparent)
Spectral Type: A0m...
Distance: 8.60 Light Years
Parallax: 0.37921"

At J1991.25 this should be the same as Hipparcos catalogue value:
H| 32349| |06 45 09.25|-16 42 47.3

I don't see this Hipparcos value not on date/tiem 1991/1/1 18:00. I see it
in Stellariums' RA/DE(J2000) and a little differently in 'RA/DE(of date)'.

All the best,

Victor

On 13 February 2013 18:45, Alexander Wolf <email address hidden>wrote:

> When you change date to epoch J1991.25 then you need see RA/Dec on date,
> not (J2000).
>
> --
> 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:
> New
>
> 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>
>
> To manage notifications about this bug go to:
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>