A Mid-Infrared Search for Substellar Companions of Nearby Planet-Host Stars
Hulsebus et al
Determining the presence of widely separated substellar-mass companion is crucial to understand the dynamics of inner planets in extrasolar planetary systems (e.g. to explain their high mean eccentricity as inner planets are perturbed by the Kozai mechanism). We report the results of our Spitzer/Infrared Array Camera (IRAC) imaging search for widely separated (10 to 25′′) substellar-mass companions for 14 planet-host stars within 15 pc of the Sun. Using deep 3.6 and 4.5 μm observations in subarray mode, we found one object in the field of 47 UMa with [3.6]−[4.5] color similar to a T5 dwarf, which is, however, unlikely to share common proper motion with 47 UMa. We also found three objects with brown-dwarf-like [3.6]−[4.5] color limits in the fields of GJ 86, HD 160691, and GJ 581, as well as another in the field of HD 69830 for which we have excluded common proper motion. We provide model-based upper mass limits for unseen objects around all stars in our sample, with typical sensitivity to 10 MJ objects from a projected separation of 50 to 300 au from the parent star. We also discuss our data analysis methods for point-spread-function subtraction, image co-alignment, and artifact subtraction of IRAC subarray images.
Thursday, February 6, 2014
Brown Dwarf Candidates Found Near Gliese 86, HD 160691, Gliese 581; In Field of View of HD 69830 and 47 UMa
Posted by Will Baird at 4:00 PM
Labels: 47 UMa, brown dwarf, gliese 581, gliese 86, HD 160691, HD 69830
Subscribe to: Post Comments (Atom)
Post a Comment
Note: Only a member of this blog may post a comment.