The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. VIII. Type II Cepheids in the Small Magellanic Cloud

• Autorzy: Soszyński I. , Udalski A. , Szymański M. K. , Kubiak M. , Pietrzyński G. , Wyrzykowski Ł. , Ulaczyk K. , Poleski R.
• Języki publikacji: EN

Abstrakty

EN

The eighth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains type II Cepheids in the Small Magellanic Cloud (SMC). The sample consists of 43 objects, including 17 BL Her, 17 W Vir and 9 RV Tau stars (first examples ever found in the SMC). Seven stars have been classified as peculiar W Vir stars - a recently identified subclass of type II Cepheids. These stars have distinctive light curves, are brighter and bluer than the ordinary W Vir variables. We confirm that a large fraction of the peculiar W Vir stars are members of binary systems. Three type II Cepheids exhibit eclipsing variations superimposed on the pulsation light curves, and three other objects show long-period ellipsoidal variability. All stars with the indication of binarity display secondary periods which may be interpreted as amplitude and/or phase modulations of the pulsation light curves with periods equal to the orbital periods or half the orbital periods. We do not have any model for these modulations, however this phenomenon rules out a possibility of the optical blends of a pulsating star and a binary system. For each object the multi-epoch V- and I-band photometry collected over 8 or 13 years of observations and finding charts are available to the astronomical community from the OGLE Internet archive.

Słowa kluczowe

EN

stars: variables; Cepheids; stars: oscillations; stars: population II; Magellanic Clouds

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2010
• Tom: Vol. 60, No. 2
• Strony: 91--107
• Opis fizyczny: Bibliogr. 25 poz., rys., tab.

Twórcy

autor

Soszyński I.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Udalski A.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Szymański M. K.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Kubiak M.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Pietrzyński G.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
• Universidad de Concepción, Departamento de Astronomia, Casilla 160-C, Concepción, Chile

autor

Wyrzykowski Ł.

• Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

autor

Ulaczyk K.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Poleski R.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

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