2010
HR 7355 - another rapidly braking He-strong CP star?
MIKULÁŠEK, Zdeněk, Jiří KRTIČKA, Gregory W. HENRY, Stephan N. DE VILLIERS, Ernst PAUNZEN et. al.Základní údaje
Originální název
HR 7355 - another rapidly braking He-strong CP star?
Název česky
HR 7355 - další rychle se brzdící heliová CP hvězda?
Autoři
MIKULÁŠEK, Zdeněk (203 Česká republika, garant, domácí), Jiří KRTIČKA (203 Česká republika, domácí), Gregory W. HENRY (840 Spojené státy), Stephan N. DE VILLIERS (710 Jižní Afrika), Ernst PAUNZEN (40 Rakousko) a Miloslav ZEJDA (203 Česká republika, domácí)
Vydání
Astronomy and Astrophysics, Paris, EDP Sciences, 2010, 0004-6361
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Francie
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 4.425
Kód RIV
RIV/00216224:14310/10:00040496
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000275752400097
Klíčová slova česky
stars: chemically peculiar; stars: variables: general; stars: individual: HR 7355; stars: rotation
Klíčová slova anglicky
stars: chemically peculiar; stars: variables: general; stars: individual: HR 7355; stars: rotation
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 15. 3. 2012 16:57, prof. RNDr. Zdeněk Mikulášek, CSc.
V originále
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.
Česky
Over two years, 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, with amplitudes 0.035(4), 0.036(4), and 0.038(3) mag in B, Hp, and V, respectively. The light curves are 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 briefly describe and discuss the cause of the rapid rotational braking of the star.
Návaznosti
| IAA301630901, projekt VaV |
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| MEB060807, projekt VaV |
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