The final helium flash object Sakurai: Photometric behavior and physical characteristics

被引:55
作者
Duerbeck, HW
Benetti, S
Gautschy, A
vanGenderen, AM
Kemper, C
Liller, W
Thomas, T
机构
[1] EUROPEAN SO OBSERV,SANTIAGO 19,CHILE
[2] UNIV BASEL,INST ASTRON,CH-4102 BINNINGEN,SWITZERLAND
[3] LEIDEN OBSERV,NL-2300 RA LEIDEN,NETHERLANDS
[4] MINIST EDUC CHILE,INST ISAAC NEWTON,SANTIAGO,CHILE
[5] SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218
[6] UNIV MUNSTER,D-4400 MUNSTER,GERMANY
关键词
D O I
10.1086/118595
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Six-color broadband photometry of Sakurai's Object, a star that underwent a final helium flash in late 1994, has been carried out since 1996 February. The light curves show that Sakurai's Object is continuously cooling while it slowly expands and slightly increases its luminosity. The distance is estimated to be 8 kpc, the interstellar extinction EB-V=0.53, and the luminosity in early 1997 is 10 000 L.. The high luminosity indicates that the white dwarf is quite massive. With the assumption of a slightly accelerated photospheric expansion a realistic description of the outburst light curve is achieved, Superimposed on the gradual brightness changes are variations with amplitudes of up to 0.1 mag and cycle lengths of 63, 23, 14, and 8 days. In spite of the fact that no persistent periodicities could be detected, pulsational studies show that such cyclic changes can be used to constrain stellar parameters such as mass, luminosity, and chemical abundances. (C) 1997 American Astronomical Society.
引用
收藏
页码:1657 / 1665
页数:9
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