Tycho variables stars (Piquard 2001)

Details Tycho variables stars (Piquard 2001) Tycho variables stars (Piquard 2001)

Nov 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001ycat.2233....0p&link_type=abstract

VizieR On-line Data Catalog: II/233. Originally published in: PhD Dissertation, Strasbourg, (2001)

Physics

1

Stars: Variable, Magnitudes

Scientific paper

We present the results of the classification procedure described in Piquard's PhD thesis applied to the 1091 stars presented in Piquard et al. (2001. Cat. ). In those six tables we give indication of variability type for all the stars detected as variables in Piquard et al. (2001, Cat. ). First of all, we looked for periodic signals in the light curves using adapted Renson's (Renson, 1978A&A....63..125R) and Stellingwerf's (Stellingwerf, 1978ApJ...224..953S) methods applied to the tree different photometric bands from Tycho (Cat. ): T, BT, VT (the T band is defined from the added count-rates in the BT and VT channels, Grossmann et al.. 1995A&A...304..110G). Then we developed a semi-automatic method using 5 parameters (Period, color index, reduced proper motion from Tycho-2 catalogue (Cat. ), 2 indicators of the shape of the light curve) and a maximum likelihood method, combined with a careful look on the light curves. Finaly, the identification of the variability type is kept only if the resulting light curve is convincing (periodic the star has the P status, if not periodic the star has the U status); else we need more information about the star and is has the A status. All this identifications are indications since the quality of the light curves are often poor, particularly when the star is fainter than T=10. (2 data files).