MIKULÁŠEK, Zdeněk, Jiří KRTIČKA, Gregory W. HENRY, Stephan N. DE VILLIERS, Ernst PAUNZEN a Miloslav ZEJDA. HR 7355 - another rapidly braking He-strong CP star? Astronomy and Astrophysics. Paris: EDP Sciences, 2010, roč. 2010, č. 511, s. L7, 4 s. ISSN 0004-6361. Dostupné z: https://dx.doi.org/10.1051/0004-6361/200913832. |
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@article{876074, author = {Mikulášek, Zdeněk and Krtička, Jiří and Henry, Gregory W. and de Villiers, Stephan N. and Paunzen, Ernst and Zejda, Miloslav}, article_location = {Paris}, article_number = {511}, doi = {http://dx.doi.org/10.1051/0004-6361/200913832}, keywords = {stars: chemically peculiar; stars: variables: general; stars: individual: HR 7355; stars: rotation}, language = {eng}, issn = {0004-6361}, journal = {Astronomy and Astrophysics}, title = {HR 7355 - another rapidly braking He-strong CP star?}, volume = {2010}, year = {2010} }
TY - JOUR ID - 876074 AU - Mikulášek, Zdeněk - Krtička, Jiří - Henry, Gregory W. - de Villiers, Stephan N. - Paunzen, Ernst - Zejda, Miloslav PY - 2010 TI - HR 7355 - another rapidly braking He-strong CP star? JF - Astronomy and Astrophysics VL - 2010 IS - 511 SP - L7 EP - L7 PB - EDP Sciences SN - 00046361 KW - stars: chemically peculiar KW - stars: variables: general KW - stars: individual: HR 7355 KW - stars: rotation N2 - We acquired 114 new BV observations of HR 7355 at observatories in Arizona, U.S.A and Cape Town, South Africa. We performed period analyses of the new observations along with new analyses of 732 archival measurements from the Hipparcos and ASAS projects. We find that the light curves of HR 7355; in various filters are quite similar, double-peaked, with unevenly deep minima. We substantially refine the rotational period to be P = 0.5214410(4)d, indicating that HR 7355gt; is the most rapidly rotating CP star known. Our period analyses reveal a possible lengthening of the rotational period with dP/dt/P = 2.4(8)x10-6 yr-1. We conclude that the shape and amplitude of HR 7355; light curves are typical of magnetic He-strong CP stars, for which light variations are the result of photospheric spots on the surface of a rotating star. We hypothesise that the light variations are caused mainly by an uneven distribution of overabundant helium on the star's surface. We discuss the cause of the rapid rotational braking of the star. ER -
MIKULÁŠEK, Zdeněk, Jiří KRTIČKA, Gregory W. HENRY, Stephan N. DE VILLIERS, Ernst PAUNZEN a Miloslav ZEJDA. HR 7355 - another rapidly braking He-strong CP star? \textit{Astronomy and Astrophysics}. Paris: EDP Sciences, 2010, roč.~2010, č.~511, s.~L7, 4 s. ISSN~0004-6361. Dostupné z: https://dx.doi.org/10.1051/0004-6361/200913832.
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