2007/10/29 by D. E. Trilling, G. Bryden, C. A. Beichman +7 · 9 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/525514
published as Astrophys.J.674:1086-1105,2008 · ApJ, in press
arxiv created 2007/10/29 · openalex publication_date 2008/02/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have observed nearly 200 FGK stars at 24 and 70 μm with the Spitzer Space Telescope . We identify excess infrared emission, including a number of cases where the observed flux is more than 10 times brighter than the predicted photospheric flux, and interpret these signatures as evidence of debris disks in those systems. We combine this sample of FGK stars with similar published results to produce a sample of more than 350 main sequence AFGKM stars. The incidence of debris disks is 4.2 + 2.0 −1.1 % at 24 μm for a sample of 213 Sun-like (FG) stars and 16.4 + 2.8 −2.9 % at 70 μm for 225 Sun-like (FG) stars. We find that the excess rates for A, F, G, and K stars are statistically indistinguishable, but with a suggestion of decreasing excess rate toward the later spectral types; this may be an age effect. The lack of strong trend among FGK stars of comparable ages is surprising, given the factor of 50 change in stellar luminosity across this spectral range. We also find that the incidence of debris disks declines very slowly beyond ages of 1 billion years.