Periodic variable stars in CoRoT field LRa02 observed with BEST II ^*

¹ Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt, Rutherfordstr. 2, 12489 Berlin, Germany e-mail: petr.kabath@dlr.de
² Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
³ Astronomisches Institut, Ruhr-Universität Bochum, 44780 Bochum, Germany
⁴ Depto. Física, Universidad Católica del Norte PO 1280, Antofagasta, Chile
⁵ Thüringer Landessternwarte Tautenburg, 07778 Tautenburg, Germany

Received: 20 February 2009
Accepted: 24 June 2009

Abstract

Context. The Berlin Exoplanet Search Telescope II (BEST II) is a small wide field-of-view photometric survey telescope system located at the Observatorio Cerro Armazones, Chile. The high duty cycle combined with excellent observing conditions and millimagnitude photometric precision makes this instrument suitable for ground based support observations for the CoRoT space mission.

Aims. Photometric data of the CoRoT LRa02 target field collected between November 2008 and March 2009 were analysed for stellar variability. The presented results will help in the future analysis of the CoRoT data, particularly in additional science programs related to variable stars.

Methods. BEST II observes selected CoRoT target fields ahead of the space mission. The photometric data acquired are searched for stellar variability, periodic variable stars are identified with time series analysis of the obtained stellar light curves.

Results. We obtained the light curves of  stars in the CoRoT LRa02 field over 41 nights. Variability was detected in light curves of 3726 stars of which 350 showed a regular period. These stars are, with the exception of 5 previously known variable stars, new discoveries.