Deep imaging survey of the environment of alpha Centauri. II. CCD imaging with the NTT-SUSI2 camera

P. Kervella (1) , F. Thévenin (2)

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
2 CASSIOPEE - Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides

Context: Thanks to its proximity, alpha Centauri is an outstanding target for an imaging search for extrasolar planets.
Aims: We searched for faint comoving companions to alpha Cen located at angular distances of a few tens of arcseconds, up to 2-3 arcmin.
Methods: We obtained CCD images from the NTT-SUSI2 instrument in the Bessel V, R, I, and Z bands, and archive data from 2MASS.
Results: We present a catalogue of the detected objects inside a 5.5 arcmin box around this star. A total of 4313 sources down to m_V ≈ 24 and m_I ≈ 22 were detected in the SUSI2 images. The infrared photometry of part of these sources has been extracted from the 2MASS images.
Conclusions: .No comoving companion to alpha Centauri were detected between 100 and 300 AU, down to a maximum mass of ≈15 times Jupiter. We also mostly exclude the presence of a companion more massive than 30 M_J between 50 and 100 AU.

Domaines: Astrophysique [astro-ph]

P. Kervella, F. Thévenin. Deep imaging survey of the environment of alpha Centauri. II. CCD imaging with the NTT-SUSI2 camera. Astronomy and Astrophysics - A&A, 2007, 464, pp.373-375. ⟨10.1051/0004-6361:20066432⟩. ⟨hal-00388124⟩