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The Beta Pictoris Phenomenon in A-Shell Stars: Detection of Accreting GasWe present the results of an expanded survey of A-shell stars using IUE high-dispersion spectra and find accreting, circumstellar gas in the line of sight to nine stars, in addition to the previously identified beta Pic, HR 10, and 131 Tau, which can be followed to between +70 and 100 km/s relative to the star. Two of the program stars, HD 88195 and HD 148283, show variable high-velocity gas. Given the small number of IUE spectra for our program stars, detection of high-velocity, accreting gas in 2/3 of the A-shell stars sampled indicates that accretion is an intrinsic part of the A-shell phenomenon and that beta Pic is not unique among main-sequence A stars in exhibiting such activity. Our program stars, as a group, have smaller column densities of high-velocity gas and smaller near-IR excesses compared with beta Pic. These features are consistent with greater central clearing of a remnant debris disk, compared with beta Pic, and suggest that the majority of field A-shell stars are older than beta Pic.
Document ID
19990078585
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Grady, C. A.
(Eureka Scientific, Inc. Oakland, CA United States)
Perez, Mario R.
(Applied Research Corp. Landover, MD United States)
Talavera, A.
(Laboratorio de Astrofisica Espacial y Fisica Fundamental Madrid, Spain)
McCollum, B.
(Computer Sciences Corp. Lanham, MD United States)
Rawley, L. A.
(Computer Sciences Corp. Lanham, MD United States)
England, M. N.
(Computer Sciences Corp. Lanham, MD United States)
Schlegel, M.
(Computer Sciences Corp. Lanham, MD United States)
Date Acquired
August 19, 2013
Publication Date
November 1, 1996
Publication Information
Publication: Astrophysical Journal
Publisher: American Astronautical Society
Volume: 471
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NASW-4756
Distribution Limits
Public
Copyright
Other

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