Identification of Variable Stars inCOROT's First Main Observing Field (LRc1)

Abstract

The COROT space mission will monitor several target fields for up to 150 days to perform asteroseismology and to search for extrasolar planets by photometric transits. Variable stars in the target fields are important objects for additional scientific studies but can also disturb the search for planetary transits. A variability characterization of the target fields prior to COROT observations is therefore important for two reasons: to find interesting variable stars to monitor further and to make an analysis of the impact of the variable stars on detecting extrasolar planet transits with COROT. The Berlin Exoplanet Search Telescope ( BEST ) is a small wide-angle telescope dedicated to highprecision photometry. It has observed a 9 deg 2 field of view centered at ( ; ) ¼ (19 h 00 m 00:0 s ; þ00 01 0 55:2 00 ) (J2000.0) over 98 nights to search for variable stars in the surroundings of the first long-run target field ( LRc1) of the COROT space mission. In this data set we identified 92 periodic variable stars, 86 of which are new discoveries and 6 of which are known from the General Catalogue of Variable Stars (GCVS). For five of the GCVS stars, variability could not be confirmed. Forty-three of the 92 detected periodic variable stars are identified as eclipsing binaries. We have evaluated the completeness of our survey for eclipsing binaries by comparing it to the expected fraction of eclipsing binaries based on Hipparcos observations. From this evaluation we show that the BEST data set presented here has a completeness of 20%Y30% for periods longer than 1 day and is complete relative to Hipparcos for short-period binaries.

Planetary transit candidates in CoRoT-LRc01 field

“…The scientific task of the detection teams is to provide a characterized set of planetary transiting candidates; although as a natural by-product they build a list of identified eclipsing binaries which is provided here. Some of the binaries (such as E1_1922, E2_0170, E2_1450, E2_3052, E1_1262, and E2_0169) have already been observed by Karoff et al (2007) within the Berlin Exoplanet Search Telescope (BEST) survey of variable stars in the CoRoT fields. Among the binaries in the list, the following are clearly eccentric: E1_1273, E1_1352, E1_1422, E1_2978, E1_3418, E1_3671, E1_4583, E1_5097, E1_5173, E2_0258, E2_0667, E2_1661, E2_1954, E2_2257, E2_2631, E2_2871, E2_3956, E2_3995, E2_5245.…”

A Variable Star Census in a Perseus Field

“…project (Kabath et al 2007;Karoff et al 2007;Kabath et al 2008Kabath et al , 2009bKabath et al , 2009aRauer et al 2010).…”

Ground-based photometry of space-based transit detections: photometric follow-up of the CoRoT mission

“…Deeg et al 2000;Martín et al 2001;Zapatero Osorio et al 2004;Steinfadt et al 2008;Deeg et al 2008;Rabus et al 2009), a module that derives observed on-off brightness differences has been added for the CoRoT follow-up. Furthermore, it includes a calculation of the contamination factors k c from a simulated CoRoT (Kabath et al 2007;Karoff et al 2007;Kabath et al 2008Kabath et al , 2009bKabath et al 2009a;Rauer et al 2009) which are routinely checked against the detections from CoRoT. They will also be used for future surveying of CoRoT-short run fields.…”