Issue |
A&A
Volume 400, Number 1, March II 2003
|
|
---|---|---|
Page(s) | L13 - L16 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20030132 | |
Published online | 24 February 2003 |
Letter to the Editor
Model atmosphere analysis of the extreme DQ white dwarf GSC2U J131147.2+292348
1
INAF, Osservatorio Astronomico di Torino, 10025 Pino Torinese, Italy
2
Institut für Theoretische Physik und Astrophysik, Universität Kiel, 24098 Kiel, Germany
3
Cambridge Astronomical Survey Unit, Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK
Corresponding author: D. Carollo, carollo@to.astro.it
Received:
12
January
2003
Accepted:
28
January
2003
A new model atmosphere analysis for the peculiar DQ white dwarf discovered by Carollo et al. ([CITE]) is presented. The
effective temperature and carbon abundance have been estimated by
fitting both the photometric data () and a low resolution spectrum (
Å)
with a new model grid for helium-rich white dwarfs with traces of
carbon (DQ stars). We estimate
K
and
, which make
GSC2U J131147.2+292348 the coolest DQ star ever observed. This
result indicates that the hypothetical transition from C2 to C2H molecules around
= 6000 K, which was inferred to
explain the absence of DQ stars at lower temperatures, needs to be
reconsidered.
Key words: white dwarfs / techniques: spectroscopic / stars: kinematics / stars: individual: GSC2U J131147.2+292348
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.