2006/12/19 by M. M. Moerchen, Margaret M. Moerchen, C. M. Telesco +2
Chemistry · Physics and Astronomy · #Asteroid belt #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Chemistry #Debris #Debris disk #Flux (metallurgy) #Infrared #Meteorology #Physics #Planet #Planetary system #Planetesimal #Population #RADIUS #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/511955
published as Astrophys.J.655:L109-L112,2007 · 4 pages, 1 figure, accepted for publication in ApJ Letters
arxiv created 2006/12/19 · openalex publication_date 2007/01/11 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present subarcsecond-resolution mid-infrared images of the debris disk surrounding the 230 Myr old A star ζ Lep. Our data obtained with T-ReCS at Gemini South show the source to be unresolved at 10.4 μm but clearly extended at 18.3 μm. Quadratic subtraction of the PSF profile from that of ζ Lep implies a characteristic radius for the dust disk of 3 AU, which is comparable in size to our solar system's asteroid belt. Simple models suggest that the 18 μm flux is well approximated by two contiguous annuli of mid-infrared-emitting dust from 2-4 and 4-8 AU with a 3 : 1 flux ratio for the annuli, respectively. We consider two scenarios for the collisions that must be resupplying the dust population: (1) continuous "steady state" grinding of planetesimals and (2) an isolated cataclysmic collision. We determine that radiation pressure and subsequent collisions are the dominant determinants of the disk morphology in either case and that Poynting-Robertson drag is comparatively insignificant.