BIB-VERSION:: AST-PP-v1.0
ID:: epreps.stsci//prep1196
ENTRY:: March 9, 1998
TITLE:: HD 98800: A Unique Stellar System of Post-T Tauri Stars
SUBTITLE::
AUTHOR:: Soderblom, David R. (1)
AUTHOR:: King, Jeremy R. (1)
AUTHOR:: Siess, Lionel (1) (2)
AUTHOR:: Noll, Keith S. (1)
AUTHOR:: Gilmore, Diane M. (1)
AUTHOR:: Henry, Todd J. (1)
AUTHOR:: Nelan, Edmund (1)
AUTHOR:: Burrows, Christopher J. (1)
AUTHOR:: Brown, Robert A. (1)
AUTHOR:: Perryman, M. A. C. (3)
AUTHOR:: Benedict, G. Fritz (4)
AUTHOR:: McArthur, Barbara J. (4)
AUTHOR:: Franz, Otto G. (5)
AUTHOR:: Wasserman, Laurence H. (5)
AUTHOR:: Jones, Burton F. (6)
AUTHOR:: Latham, David W. (7)
AUTHOR:: Torres, Guillermo (7)
AUTHOR:: Stefanik, Robert P. (7)
AFFIL:: (1) Space Telescope Science Institute 3700 San Martin Dr. Baltimore, MD 21218 USA
AFFIL:: (2) Laboratoire d'Astrophysique de l'Observatoire de Grenoble, Université Joseph Fournier, BP53, F-38041, Grenoble Cedex, France
AFFIL:: (3) Astrophysics Division, European Space Agency, ESTEC Noordwijk 2200AG, The Netherlands
AFFIL:: (4) McDonald Observatory, University of Texas, Austin TX 78712
AFFIL:: (5) Lowell Observatory, 1400 W. Mars Hill Rd, Flagstaff AZ 86001
AFFIL:: (6) University of California Observatories/Lick Observatory Board of Studies in Astronomy, Astrophysics University of California Santa Cruz CA 95064
AFFIL:: (7) Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge MA 02138
DATE:: December 1997
JOURNAL:: To appear in: The Astrophysical Journal
SUBMITTED:: 20 August 1997
ACCEPTED:: 1 November 1997
OTHER_ACCESS::
COPYRIGHT:: Copyright 1997 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.
LANGUAGE:: English
ABSTRACT::
HD 98800 is a system of four stars, and it has a large infrared
excess that is thought to be due to a dust disk within the system. In
this paper we present new astrometric observations made with
Hipparcos as well as photometry from Hubble Space Telescope
WFPC2 images. Combining these observations and reanalyzing
previous work allows us to estimate the age and masses of the stars in
the system. Uncertainty in these ages and masses results from
uncertainty in the temperatures of the stars and any reddening they
may have. We find that HD 98800 is most probably about 10 Myr
old, although it may be as young as 5 Myr or as old as
20 Myr. The stars in HD 98800 appear to have
metallicities that are about solar. An age of 10 Myr means
that HD 98800 is a member of the post-T Tauri class
of objects, and we argue that the stars in HD 98800 can help
us understand why post-T Tauris have been so elusive.
HD 98800 may have formed in the Centaurus star-forming
region, but it is extraordinary in being so young and yet so far from
where it was born.
END:: epreps.stsci//prep1196