Overview of semi-sinusoidal stellar variability with the CoRoT satellite ⋆,⋆⋆
1
Departamento de FísicaUniversidade Federal do Rio Grande do
Norte,
59072-970
Natal,
RN,
Brazil
e-mail: renan@dfte.ufrn.br
2
Departamento de Astronomía y Astrofísica, Pontificia Universidad
Católica de Chile, Av. Vicuña
Mackenna 4860, 782-0436 Macul, Santiago, Chile
3
The Milky Way Millennium Nucleus, Av. Vicuña Mackenna 4860,
782-0436 Macul, Santiago, Chile
4
LESIA, UMR 8109 CNRS, Observatoire de Paris, UVSQ, Université
Paris-Diderot, 5 place J.
Janssen, 92195
Meudon,
France
5
Departamento de Física, Facultad de Ciencias Básicas, Universidad
Metropolitana de la Educacion, Av.
José Pedro Alessandri 774, 7760197 Ñuñoa, Santiago, Chile
6
Universidade de São Paulo/IAG-USP, rua do Matão, 1226, Cidade
Universitária, 05508-900
São Paulo, SP, Brazil
7
IFPB – Instituto Federal de Educação, Ciência e Tecnologia da Paraíba, Av. Primeiro de Maio 720,
58015-430
João Pessoa, PB, Brazil
8
European Southern Observatory, Casilla 19001, Santiago, Chile
9
Department of Physics and Astronomy Uppsala University,
Box 516,
751 20
Uppsala,
Sweden
10
Universidade Federal do Rio de Janeiro, Observatório do Valongo,
Ladeira do Pedro Antonio,
43, 20080-090
Rio de Janeiro,
Brazil
11
Center for Radio Astronomy and Astrophysics Mackenzie,
Universidade Presbiteriana Mackenzie, Rua da Consolação, 896
São Paulo, SP, Brazil
Received: 13 April 2012
Accepted: 24 April 2013
Context. To date, the CoRoT space mission has produced more than 124 471 light curves. Classifying these curves in terms of unambiguous variability behavior is mandatory for obtaining an unbiased statistical view on their controlling root-causes.
Aims. The present study provides an overview of semi-sinusoidal light curves observed by the CoRoT exo-field CCDs.
Methods. We selected a sample of 4206 light curves presenting well-defined semi-sinusoidal signatures. The variability periods were computed based on Lomb-Scargle periodograms, harmonic fits, and visual inspection.
Results. Color–period diagrams for the present sample show the trend of an increase of the variability periods as long as the stars evolve. This evolutionary behavior is also noticed when comparing the period distribution in the Galactic center and anti-center directions. These aspects indicate a compatibility with stellar rotation, although more information is needed to confirm their root-causes. Considering this possibility, we identified a subset of three Sun-like candidates by their photometric period. Finally, the variability period versus color diagram behavior was found to be highly dependent on the reddening correction.
Key words: stars: variables: general / stars: rotation / techniques: photometric
The CoRoT space mission was developed and is operated by the French space agency CNES, with the participation of ESA’s RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain.
Table 2 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/555/A63
© ESO, 2013