2007A&A...464..373K

Thanks to its proximity, α Centauri is an outstanding target for an imaging search for extrasolar planets. We searched for faint comoving companions to α Cen located at angular distances of a few tens of arcseconds, up to 2-3arcmin. We obtained CCD images from the NTT-SUSI2 instrument in the Bessel V, R, I, and Z bands, and archive data from 2MASS. We present a catalogue of the detected objects inside a 5.5arcmin 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. No comoving companion to α Centauri were detected between 100 and 300AU, down to a maximum mass of ≃15 times Jupiter. We also mostly exclude the presence of a companion more massive than 30M_J between 50 and 100AU.