Discovery of Gas Accretion onto Stars in 13 Myr old h and χ Persei

, , , , and

Published 2007 October 4 © 2007. The American Astronomical Society. All rights reserved. Printed in U.S.A.
, , Citation Thayne Currie et al 2007 ApJ 669 L33 DOI 10.1086/523595

1538-4357/669/1/L33

Abstract

We report the discovery of accretion disks associated with ~13 Myr old intermediate/low-mass stars in h and χ Persei. Optical spectroscopy of ~5000 stars in these clusters and a surrounding halo population reveal 32 A-K stars with Hα emission. Matching these stars with 2MASS and optical photometry yields 25 stars with the highest probability of cluster membership and EW(Hα) ≥ 5 Å. Sixteen of these sources have EW(Hα) ≥ 10 Å. The population of accreting sources is strongly spectral type dependent: Hα emission characteristic of accretion, especially strong accretion [EW(Hα) ≥ 10 Å], is much more prevalent around stars later than G0. Strong Hα emission from accretion is typically associated with redder Ks - [8] colors. The existence of accreting pre-main-sequence stars in h and χ Persei implies that circumstellar gas in some systems, especially those with primaries later than G5 spectral type, can last longer than 10-15 Myr.

Export citation and abstract BibTeX RIS

Please wait… references are loading.
10.1086/523595