Pulsating stars in ω Centauri. Near-IR properties and period-luminosity relations

Autor: Navarrete Camila, Catelan Márcio, Contreras Ramos Rodrigo, Alonso-García Javier, Gran Felipe, Dékány István, Minniti Dante
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: EPJ Web of Conferences, Vol 152, p 07005 (2017)
Druh dokumentu: article
ISSN: 2100-014X
DOI: 10.1051/epjconf/201715207005
Popis: ω Centauri (NGC 5139) contains many variable stars of different types, including the pulsating type II Cepheids, RR Lyrae and SX Phoenicis stars. We carried out a deep, wide-field, near-infrared (IR) variability survey of ω Cen, using the VISTA telescope. We assembled an unprecedented homogeneous and complete J and KS near-IR catalog of variable stars in the field of ω Cen. In this paper we compare optical and near-IR light curves of RR Lyrae stars, emphasizing the main differences. Moreover, we discuss the ability of near-IR observations to detect SX Phoenicis stars given the fact that the amplitudes are much smaller in these bands compared to the optical. Finally, we consider the case in which all the pulsating stars in the three different variability types follow a single period-luminosity relation in the near-IR bands.
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