ON THE OCCURRENCE RATE OF HOT JUPITERS IN DIFFERENT STELLAR ENVIRONMENTS

Abstract

Many Hot Jupiters (HJs) are detected by the Doppler and the transit\ntechniques. From surveys using these two techniques, however, the measured HJ\noccurrence rates differ by a factor of two or more. Using the California Planet\nSurvey sample and the Kepler sample, we investigate the causes for the\ndifference of HJ occurrence rate. First, we find that $12.8\\%\\pm0.24\\%$ of HJs\nare misidentified in the Kepler mission because of photometric dilution and\nsubgiant contamination. Second, we explore the differences between the Doppler\nsample and the Kepler sample that can account for the different HJ occurrence\nrate. Third, we discuss how to measure the fundamental HJ occurrence rates by\nsynthesizing the results from the Doppler and Kepler surveys. The fundamental\nHJ occurrence rates are a measure of HJ occurrence rate as a function of\nstellar multiplicity and evolutionary stage, e.g., the HJ occurrence rate for\nsingle and multiple stars or for main sequence and subgiant stars. While we\nfind qualitative evidence that HJs occur less frequently in subgiants and\nmultiple stellar systems, we conclude that our current knowledge of stellar\nproperties and stellar multiplicity rate is too limited for us to reach any\nquantitative result for the fundamental HJ occurrence rates. This concern\nextends to $\\eta_{\\rm{Earth}}$, the occurrence rate of Earth-like planets.\n