Laser Guide Star Adaptive Optics Imaging Polarimetry of Herbig Ae/Be Stars
Marshall D. Perrin,1,2*
James R. Graham,1,2
Paul Kalas,1,2
James P. Lloyd,2,3
Claire E. Max,2,4
Donald T. Gavel,2,5
Deanna M. Pennington,2,4
Elinor L. Gates2,6
We have used laser guide star adaptive optics and a near-infrared dual-channel imaging polarimeter to observe light scattered in the circumstellar environment of Herbig Ae/Be stars on scales of 100 to 300 astronomical units. We revealed a strongly polarized, biconical nebula 10 arc seconds (6000 astronomical units) in diameter around the star LkH
198 and also observed a polarized jet-like feature associated with the deeply embedded source LkH 198-IR. The star LkH 233 presents a narrow, unpolarized dark lane consistent with an optically thick circumstellar disk blocking our direct view of the star. These data show that the lower-mass T Tauri and intermediate mass Herbig Ae/Be stars share a common evolutionary sequence.
1 Astronomy Department, University of California Berkeley, Berkeley, CA 94720, USA.
2 National Science Foundation Center for Adaptive Optics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
3 Astronomy Department, California Institute of Technology, 1201 East California Boulevard, Pasadena, CA 91125, USA.
4 Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA.
5 Laboratory for Adaptive Optics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
6 University of California Observatories/Lick Observatory, Post Office Box 85, Mount Hamilton, CA 95140, USA.
* To whom correspondence should be addressed. E-mail: mperrin{at}astro.berkeley.edu
