Volume 461, Number 2, January II 2007
|Page(s)||665 - 668|
|Section||Stellar structure and evolution|
|Published online||13 November 2006|
A direct and differential imaging search for sub-stellar companions to ϵ Indi A
Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany e-mail: email@example.com, firstname.lastname@example.org, email@example.com
2 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile
3 W.M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, Hawaii 96743
4 INAF - Osservatorio Astrofisico di Arecetri, L.go E. Fermi 5, 50125 Firenze, Italy
5 Steward Observatory, University of Arizona, Tucson, Arizona 85721, USA
6 McDonald Observatory, The University of Texas at Austin, Austin, TX 78712-1083, USA
Accepted: 27 October 2006
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 MJ 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 . The photometry for the candidate companion yields mH = (16.45 ± 0.04) mag and = (15.41 ± 0.06) mag, respectively. Those magnitudes and the resulting color () = (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.
Key words: stars: low-mass, brown dwarfs / stars: fundamental parameters
© ESO, 2006
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