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Paper: |
Spitzer Observations of WTTS Disks: New Constraints on the Timescale for Planet Building |
Volume: |
352, New Horizons in Astronomy: Frank N. Bash Symposium 2005 |
Page: |
233 |
Authors: |
Cieza, L.A.; the C2D Stars Team |
Abstract: |
We report on the disk frequency of a sample of over 200 spectroscopically identified wTTs located in the IRAC and MIPS maps of the Ophiuchus, Lupus and Perseus Molecular Clouds from the Spitzer Legacy Project “From Molecular Cores to Planet-forming Disks” (c2d) Evans et al. (2003). We find that, overall, ∼20% of the wTTs in the sample have noticeable IR-excesses indicating the presence of a circumstellar disk and that all the stars with disks are younger than ∼10 Myr according to their position in the H-R diagram. Since Spitzer observations probe planet-forming regions of the disk (r ∼ 0.1—10AU) and are capable of detecting IR excesses produced by very small amounts of dust, these results provide much stronger constraints on the time available for the formation of planets than those provided by previous studies based on detections of disks in the near-IR. |
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