Photometric Determination of the Distance to the RR Lyrae LP Cam.

Abstract

Photometric observations of the nearby RR Lyrae, LP Cam, were obtained to verify that the period-luminosity relationships are still valid for RR Lyrae stars with improved parallaxes as part of a larger study. Using both obtained photometry and archival data, photometric distance estimates were made to LP Cam. When accounting for independantly measured values of interstellar reddenning, the photometric distance determined for LP Cam is not in agreement with the parallactic distance. The likely causes for this mismatch are explored and could be due to greater extinction than measured or incorrect measured effective temperatures from spectral energy distributions. An additional cause could be due to a faint proximate source to LP Cam. When E(B - V ) is changed such that the variance in distance measured between the three filters is minimized, an estimate of E(B????V ) 0:24 is achieved with distance estimates of V: 780 +/- 40pc, i: 793 +/- 41pc, z: 792 +/- 38pc which compares reasonably well with the GAIA value of 809 +/- 20pc