Bpm 24754 : a new southern zz ceti star

• Autor(a) principal: Giovannini Junior, Odilon
• Data de Publicação: 1998
• Outros Autores: Kepler, Souza Oliveira, Kanaan Neto, Antonio Nemer, Costa, A.F.M., Koester, Detlev
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/97466
• topic: Astrofisica estelar; Anãs brancas; Estrelas variaveis; Evolucao estelar; Oscilacoes; Fotometria; Stars: individual: BPM 24754; Stars: variables: other; Stars: oscillations; Stars: fundamental parameters; White dwarfs

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 pro le tting and its mass using white dwarf evolutionary models. BPM 24754 has Teff = 12,900 ± 320 K, log g = 8.04 ± 0.08, and M = 0.63 ± 0.04 Mʘ. We compare its Teff in relation to the ZZ Ceti instability strip.