A direct and differential imaging search for sub-stellar companions to ε Indi A

Abstract

We have carried out a direct and differential imaging search for sub-stellar companions to ε Indi A using the adaptive optics system NACO at the ESO VLT. The observations were carried out in September 2004 with NACO/SDI as well as with NACO's S27 camera in the H and Ks filters. The SDI data cover an area of ∼2.8″ around ε Indi A. No detection was achieved in the inner neighbourhood down to 53 MJ (5 σ confidence level) at a separation ≥0.4″(1.45 AU) and down to 21 M J for separations ≥ 1.3″ (4.7 AU). To cover a wider field of view, observations with the S27 camera and a coronagraphic mask were obtained. We detected a faint source at a separation of (7.3 ± 0.1)″ and a position angle of (302.9 ± 0.8)°. The photometry for the candidate companion yields mH = (16.45 ± 0.04) mag and mKs = (15.41 ± 0.06) mag, respectively. Those magnitudes and the resulting color (H - Ks) = (1.04 ± 0.07) mag fit best to a spectral type of L5 - L9.5 if it is bound. Observations done with HST/NICMOS by M. Endl have shown the source to be a background object. © ESO 2006.