Available formats: HTML | PDF | (gzipped) PostScript
Letter to the Editor
BPM 24754: A new Southern ZZ Ceti star *
O. Giovannini 1,
S.O. Kepler 1,
A. Kanaan 1,
A.F.M. Costa 1 and
D. Koester 2
Received 21 August 1997 / Accepted 25 September 1997
We report the discovery of a new long-period ZZ Ceti star through the analysis of photometric time series gathered on 7 nights between 1995 and 1996. The light curve displays a periodic variation with a period of 18 min in white light and the frequency analysis reveals a low frequency peak at 0.92 mHz with an amplitude varying from 0.007 to 0.025 mag present every night. BPM 24754 is the 28th known ZZ Ceti star and it has the second longest period. We have also determined its atmospheric parameters using line profile fitting and its mass using white dwarf evolutionary models. BPM 24754 has K, , and . We compare its in relation to the ZZ Ceti instability strip.
Key words: stars: individual: BPM 24754 stars: variables: other stars: oscillations stars: fundamental parameters white dwarfs
* Based on observations obtained at the Laboratório Nacional de Astrofsica/CNPq, Brazil, and at the Cerro Tololo Inter-American Observatory. CTIO is operated by AURA, Inc. under contract to the National Science Foundation.
Present address: Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901-6988, USA. E-mail: email@example.com
Send offprint requests to: O. Giovannini
© European Southern Observatory (ESO) 1998
Online publication: November 24, 1997