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Rotational Velocity and the Light Variations Period of hr 5153
Author(s) -
Mikulášek Z.
Publication year - 1976
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.19762970506
Subject(s) - physics , light curve , rotation period , radius , astrophysics , star (game theory) , period (music) , oblique case , line (geometry) , orbital inclination , optics , geometry , stars , mathematics , philosophy , linguistics , computer security , computer science , acoustics , arithmetic , binary number
HR 5153 is a peculiar star of the SrCrEu type which has not been studied in details so far. BURKE and HOWARD (1972) found that the star is variable in U and B , while in V its light does not vary. They also determined the period of the light variations P = 1 d .706. In this paper the reality of this period is discussed assuming an oblique rotator model. From the profile of the Mg II 4481 line the value of V sin i = (21 ± 5) km s −1 has been derived. From the derived value of V sin i , and assuming that the star radius is R = (2.95 ± 0.75) R ±, the angle of the inclination of the star rotational axis has been calculated to i = (14 ± 5)°. With such a small angle of inclination it is very difficult to explain the observed periodical light variations with the aid of an oblique rotator model. By the analysis of the photometric data of BURKE and HOWARD (1972) a longer period of 2 d .433 has been found, this being identical with the period obtained by the working group of W. SCHÖNEICH , by the analysis of their own photometric materials. The possibility of the double‐wave light curve is pointed out.