Constraints on Inner Disk Evolution Timescales: A Disk Census of the η Chamaeleontis Young Cluster

Author(s)
Karl E., Jr. Haisch, Ray Jayawardhana, João Alves
Abstract

We present new L'-band (3.8 μm) observations of stars in the nearby (~97 pc) young (~6 Myr) compact cluster around η Chamaeleontis, obtained with the European Southern Observatory's Very Large Telescope in Paranal, Chile. Our data, combined with J,H,Ks photometry from the Two Micron All Sky Survey, reveal that only two of the 12 members surveyed harbor L'-band excesses consistent with optically thick inner disks; both are also likely accretors. Intriguingly, two other stars with possible evidence of ongoing accretion, albeit at very low rates, do not show significant infrared excess: this may imply substantial grain growth and/or partial clearing of the inner disk region, as expected in planet formation scenarios. Our findings suggest that η Cha stars are in an epoch when disks are rapidly evolving, perhaps due to processes related to planet building, and provide further constraints on inner disk lifetimes.

Organisation(s)
Department of Astrophysics
External organisation(s)
European Southern Observatory (Germany), Utah Valley State College, University of Toronto
Journal
The Astrophysical journal Letters
Volume
627
Pages
L57-L60
ISSN
2041-8205
DOI
https://doi.org/10.1086/431898
Publication date
07-2005
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/constraints-on-inner-disk-evolution-timescales-a-disk-census-of-the--chamaeleontis-young-cluster(694534d7-9b19-4f1f-ba73-92de4c8499ad).html