Abstract
We have obtained a Gemini South T-ReCS Qa-band (18.3 μm) image and a Spitzer MIPS SED-mode observation of HD 181327, an F5/F6 V member of the ̃ 12 Myr old β Pictoris moving group. We resolve the disk in thermal emission for the first time and find that the northern arm of the disk is 1.4 times brighter than the southern arm. In addition, we detect a broad peak in the combined Spitzer IRS and MIPS spectra at 60-75 μm that may be produced by emission from crystalline water ice. We model the IRS and MIPS data using a size distribution of amorphous olivine and water ice grains (dn|da α a-2.25, with amin consistent with the minimum blowout size and amax = 20 7mu;m) located at a distance of 86.3 AU from the central star, as observed in previously published scattered-light images. Since the photodesorption lifetime for the icy particles is ̃1400 yr, significantly less than the estimated ̃12 Myr age of the system, we hypothesize that we have detected debris that may be steadily replenished by collisions among icy Kuiper Belt object-like parent bodies in a newly forming planetary system.
Original language | English (US) |
---|---|
Pages (from-to) | 539-544 |
Number of pages | 6 |
Journal | Astrophysical Journal |
Volume | 689 |
Issue number | 1 |
DOIs | |
State | Published - Dec 10 2008 |
Keywords
- Circumstellar matter
- Planetary systems: formation
- Stars: individual (HD 181327)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science