SCYON Abstract

Received on September 15 2006

Multi-site campaign on the open cluster M67. I. Observations and photometric reductions

AuthorsD. Stello (1,2,5), T. Arentoft (1,2,8), T. R. Bedding (2), M. Y. Bouzid (4), H. Bruntt (1,2,5), Z. Csubry (6), Z. E. Dind (2), S. Frandsen (1,8), R. L. Gilliland (3), A. P. Jacob (2), H. R. Jensen (1), Y. B. Kang (7), S.-L. Kim (7), L. L. Kiss (2), H. Kjeldsen (1,8), J.-R. Koo (7), J.-A. Lee (7), C.-U. Lee (7), J. Nuspl (6), C. Sterken (4), and R. Szabo (6)
Affiliation
(1) Institut for Fysik og Astronomi, Aarhus University, Denmark
(2) School of Physics, University of Sydney, Australia
(3) Space Telescope Sceince Institute, Baltimore, USA
(4) Vrije Universiteit Brussel, Belgium
(5) Department of Physics, US Air Force Academy, Colorado Springs, USA
(6) Konkoly Observatory of the Hungarian Academy of Sciences, Budapest, Hungary
(7) Korea Astronomy and Space Science Institute, Daejeon, Korea
(8) Danish AsteroSeismology Centre, Aarhus Universitet, Danmark
Accepted byMonthly Notices of the Royal Astronomical Society
Contactstello@physics.usyd.edu.au
URLhttp://www.arxiv.org/abs/astro-ph/0609340
Links M67 (NGC 2682)

Abstract

We report on an ambitious multi-site campaign aimed at detecting stellar variability, particularly solar-like oscillations, in the red giant stars in the open cluster M67 (NGC 2682). During the six-week observing run, which comprised 164 telescope nights, we used nine 0.6-m to 2.1-m class telescopes located around the world to obtain uninterrupted time-series photometry. We outline here the data acquisition and reduction, with emphasis on the optimisation of the signal-to-noise of the low amplitude (50-500 micromag) solar-like oscillations. This includes a new and efficient method for obtaining the linearity profile of the CCD response at ultra high precision (∼10 parts per million). The noise in the final time series is 0.50 mmag per minute integration for the best site, while the noise in the Fourier spectrum of all sites combined is 20 micromag. In addition to the red giant stars, this data set proves to be very valuable for studying high-amplitude variable stars such as eclipsing binaries, W UMa systems and delta Scuti stars.