A NEW CENSUS OF THE VARIABLE STAR POPULATION IN THE GLOBULAR CLUSTER NGC 2419

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/141/3/81· OSTI ID:21583211

Di Criscienzo, M ^[1]; Greco, C ^[2]; Ripepi, V; Dall' Ora, M; Marconi, M; Musella, I ^[3]; Clementini, G; Federici, L ^[4]; Di Fabrizio, L ^[5]

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1. INAF-Osservatorio Astronomico di Roma, via Frascati, 33, Monte Porzio Catone, I-00040 Rome (Italy)
2. Observatoire de Geneve, 51 ch. Des Maillettes, CH-1290 Sauverny (Switzerland)
3. INAF-Osservatorio Astronomico di Capodimonte, via Moiarello 16, I-80131 Napoli (Italy)
4. INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)
5. INAF-Centro Galileo Galilei and Telescopio Nazionale Galileo, P.O. Box 565, 38700 S. Cruz de La Palma (Spain)

We present B, V, and I CCD light curves for 101 variable stars belonging to the globular cluster NGC 2419, 60 of which are new discoveries, based on data sets obtained at the Telescopio Nazionale Galileo, the Subaru telescope, and the Hubble Space Telescope. The sample includes 75 RR Lyrae stars (38 RRab, 36 RRc, and one RRd), one Population II Cepheid, 12 SX Phoenicis variables, two {delta} Scuti stars, three binary systems, five long-period variables, and three variables of uncertain classification. The pulsation properties of the RR Lyrae variables are close to those of Oosterhoff type II clusters, consistent with the low metal abundance and the cluster horizontal branch morphology, disfavoring (but not totally ruling out) an extragalactic hypothesis for the origin of NGC 2419. The observed properties of RR Lyrae and SX Phoenicis stars are used to estimate the cluster reddening and distance, using a number of different methods. Our final value is {mu}{sub 0} (NGC 2419) = 19.71 {+-} 0.08 mag (D = 87.5 {+-} 3.3 kpc), with E(B - V) = 0.08 {+-} 0.01 mag, [Fe/H] = -2.1 dex on the Zinn and West metallicity scale, and a value of M{sub V} that sets {mu}{sub 0} (LMC) = 18.52 mag. This value is in good agreement with the most recent literature estimates of the distance to NGC 2419.

• OSTI ID: 21583211
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 3 Vol. 141; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CHARGE-COUPLED DEVICES
CLASSIFICATION
ELECTROMAGNETIC RADIATION
ELEMENTS
GALAXIES
METALS
MORPHOLOGY
RADIATIONS
SEMICONDUCTOR DEVICES
STARS
TELESCOPES
VARIABLE STARS
VISIBLE RADIATION