EDP Sciences
The CoRoT space mission: early results
Free access
Issue
A&A
Volume 506, Number 1, October IV 2009
The CoRoT space mission: early results
Page(s) 431 - 434
Section Astronomical instrumentation
DOI http://dx.doi.org/10.1051/0004-6361/200912037
Published online 15 June 2009
A&A 506, 431-434 (2009)
DOI: 10.1051/0004-6361/200912037

Removing systematics from the CoRoT light curves

I. Magnitude-dependent zero point
T. Mazeh1, 2, P. Guterman3, S. Aigrain4, S. Zucker5, N. Grinberg6, A. Alapini4, R. Alonso3, M. Auvergne7, M. Barbieri3, P. Barge3, P. Bordé8, F. Bouchy9, H. Deeg10, R. De la Reza11, M. Deleuil3, R. Dvorak12, A. Erikson13, M. Fridlund14, P. Gondoin14, L. Jorda3, H. Lammer15, A. Léger8, A. Llebaria3, P. Magain16, C. Moutou3, M. Ollivier8, M. Pätzold17, F. Pont4, D. Queloz18, H. Rauer13, 19, D. Rouan7, R. Sabo6, J. Schneider20, and G. Wuchterl19

1  Radcliffe Institute for Advanced Studies at Harvard, 8 Garden St., Cambridge, MA 02138, USA
    e-mail: mazeh@post.tau.ac.il
2  On Sabbatical leave from School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
3  Le Laboratoire d'Astrophysique de Marseille, UMR 6110 CNRS, Technopôle de Marseille-Étoile, 13388 Marseille Cedex 13, France
4  School of Physics, University of Exeter, Physics Building, Stocker Road, Exeter, Ex4 4QL, UK
5  Geophysics and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
6  School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
7  LESIA, Observatoire de Paris, 92195 Meudon, France
8  IAS, Université Paris XI, 91405 Orsay, France
9  Observatoire de Haute-Provence, 04870 St Michel l'Observatoire, France
10  IAC, 38205 La Laguna, Spain
11  ON/MCT, 20921-030, Rio de Janeiro, Brazil
12  IfA, University of Vienna, 1180 Vienna, Austria
13  Institute of Planetary Research, DLR, 12489 Berlin, Germany
14  RSSD, ESA/ESTEC, 2200 Noordwijk, The Netherlands
15  IWF, Austrian Academy of Sciences, 8042 Graz, Austria
16  IAG, Université de Liège, Liège 1, Belgium
17  RIU, Universität zu Köln, 50931 Köln, Germany
18  Observatoire de Genève, 1290 Sauverny, Switzerland
19  LUTH, Observatoire de Paris, 92195 Meudon, France
20  ZAA, TU Berlin, 10623 Berlin, Germany

Received 10 March 2009 / Accepted 28 May 2009

Abstract
This paper presents an analysis that searched for systematic effects within the CoRoT exoplanet field light curves. The analysis identified a systematic effect that modified the zero point of most CoRoT exposures as a function of stellar magnitude. We could find this effect only after preparing a set of learning light curves that were relatively free of stellar and instrumental noise. Correcting for this effect, rejecting outliers that appear in almost every exposure, and applying SysRem, reduced the stellar RMS by about 20%, without attenuating transit signals.


Key words: methods: data analysis -- techniques: photometric -- planetary systems



© ESO 2009