Align Stars in Windows Registry

[Michael Cook]

In the Windows registry: HKEY_LOCAL_MACHINE\SOFTWARE\DENNY\ACP\Align Stars

The first two entries are J2000 RA and DEC, but what are the last two entries? My guess is these have something to do with proper motion of the star.

[Dick Berg]

Hi Michael,

Yes, that's right.

From the Align Stars registry, for example, for Procyon:

RA = 7.655149460 (hours)
Dec = 5.22750767 (degrees)
PM(RA) = -4.77713 (seconds per century)
PM(Dec) = -103.458 (arcseconds per century)

If you compare this with the Hipparcos values shown in SIMBAD (at:
http://simbad.u-strasbg.fr/simbad/si...bmit=submit+id )

You have
Proper motions mas/yr:
(RA) -716.58
(Dec) -1034.60

Both are arcseconds per year, and equivalent to the above values.

[Bob Denny]

Right on, Dick!!!

[Michael Cook]

Hi Dick,

Thanks for confirming that.