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I'm trying to locate three stars inside Cassiopeia, gam cas, Schedar, and Caph. I have found gamma Cas inside the Tycho-2 catalog supp1.dat file, however when I look for Schedar or Caph I have no luck. I converted their RA and dec to decimal degree, Schedar = (10.12, 56.53) and Caph = (2.29, 59) and used the Vim command

:/|002\.

to find their location in the star catalog, but I haven't found any stars that match the RA, dec, or even visual brightness, which are 2.24 for Schedar and 2.28 for Caph. I'm kind of stuck at this point and not sure where to head from here.

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Alpha Cas (Schedar) is TYC 3663-2668-1 or HIP 3179 in the Hipparcos catalogue.

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Schedar&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

Beta Cas (Caph) is not in the Tycho-2 catalogue but is in the Hipparcos catalog as HIP 746

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Caph&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

Gamma Cas is also does not have a Tyc number but is listed as HIP 4427 in the Hipparcos catalogue.

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Cas&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

All three of these stars are right at the bright limit of the Tycho-2 catalogue.

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  • $\begingroup$ Thank you for providing the tycho refrence numbers and HIP # ! I used the actual catalog file instead of the supplementary file to locate the stars and I managed to find them. $\endgroup$ – Continuum Jul 25 '16 at 20:25
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The supplemental catalog lists stars (and other point sources) that are found in Tycho1 or Hippacos, but not in Tycho2, and is much smaller than the main catalog with about 17000 record compared with over 2.5 million in the main catalog.

However I can't but think that you are doing something very wrong in searching a data file like Tycho with vi and a regular expression. You should be using the dedicated tools designed to work with the files, such as the wcstools program scat

Schedar is in the Tycho catalog with reference TYC 3663-2668-1

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  • $\begingroup$ Thanks for your explanation on the supplemental catalog! I used scat, but had no luck in finding Schedar. I'm assuming this means that the supplement catalog does not include Schedar as it can also be found in Tycho2. I'm going to get Tycho2 & see If I can find it in there. $\endgroup$ – Continuum Jul 25 '16 at 18:47

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