SCYON Abstract

Received on May 11 2009

SPITZER/IRAC-MIPS Survey of NGC2451A and B: Debris Disks at 50-80 million years

Authors	Z. Balog, L.L. Kiss, J. Vinko, G.H. Rieke, J. Muzerolle, A. Gaspar, E.T. Young, and N. Gorlova
Affiliation	Univ. of Arizona, Univ. of Sudney, Univ. of Szeged, Univ. of Arizona, Univ. of Arizona, Univ. of Arizona, Univ. of Arizona, Univ. of Florida
Accepted by	Astrophysical Journal
Contact	zbalog@as.arizona.edu
URL	http://arxiv.org/abs/0904.2608
Links	NGC 2451A / NGC 2451B

Abstract

We present a Spitzer IRAC and MIPS survey of NGC 2451 A and B, two open clusters in the 50-80 Myr age range. We complement these data with extensive ground-base d photometry and spectroscopy to identify the cluster members in the Spitzer survey field. We find only two members with 8 micron excesses. The incidence of exc esses at 24 microns is much higher, 11 of 31 solar-like stars and 1 of 7 early-type (A) stars. This work nearly completes the debris disk surveys with Spitzer of clusters in the 30-130 Myr range. This range is of interest because it is when large planetes imal collisions may have still been relatively common (as indicated by the one that led to the formation of the Moon during this period of the evolution of the Solar System). We review the full set of surveys and find that there are only three possible cases out of about 250 roughly solar-mass stars where very large ex cesses suggest that such collisions have occurred recently.