Poster Abstracts - Kepler - NASA

Stellar Variability From DASCH vs. Kepler DataSumin Tang * , Jonathan Grindlay and Soren MeibomHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, MA 02138* stang@cfa.harvard.eduPOSTER ABSTRACTSP0710. POSTER SESSION IIDASCH (Digital Access to a Sky Century@Harvard)has similar magnitude rangeto Kepler, and therefore Kepler targets arealso covered by DASCH over 100 years.Combining the long-term variations fromDASCH, and the short-term variations fromKepler of great accuracy, enables a uniquestudy of stellar variability on the widest rangeof timescale. Here we present our study of agroup of peculiar long-term K giant variableswith slow variations over decades. Most ofthem show strong star spots and flaring activitiesin the Kepler light curves, which suggeststhat the mysterious long-term variations maybe related to strong star spots and magneticactivities which may be a new mechanism fordust formation or ejection. Preliminary studyof a few other unusual variables are also presented.Figure 2: Kepler light curve of 5095511.Figure 3: Kepler light curve of 5630212.Figure 4: Kepler light curve of 7869590.Figure 1: DASCH light curves of 5 long-termK giant variables in the Kepler FOV.This work was supported in part by NSFgrants AST-0407380 and AST-0909073 andnow also the Cornel and Cynthia K.SarosdyFund for DASCH.2011 Kepler Science Conference - NASA Ames Research Center 193