https://doi.org/10.1051/epjconf/201715207005
Pulsating stars in ω Centauri. Near-IR properties and period-luminosity relations
1 Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile
2 Millennium Institute of Astrophysics, Santiago, Chile
3 Centro de Astro-Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
4 Unidad de Astronomía, Facultad Cs. Básicas, Universidad de Antofagasta, Av. U. de Antofagasta 02800, Antofagasta, Chile
5 Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, 69120 Heidelberg, Germany
6 Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Fernandez Concha 700, Las Condes, Santiago, Chile
7 Vatican Observatory, V00120 Vatican City State, Italy
* cnavarre@astro.puc.cl
** mcatelan@astro.puc.cl
Published online: 8 September 2017
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.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
