TY - JOUR
T1 - Large-amplitude ultraviolet variations in the RR Lyrae star ROTSE-I J143753.84+345924.8
AU - Wheatley, Jonathan M.
AU - Welsh, Barry Y.
AU - Siegmund, Oswald H.W.
AU - Byun, Yong Ik
AU - Sukyoung, Y.
AU - Lee, Young Wook
AU - Madore, Barry F.
AU - Viton, Maurice
AU - Rich, R. Michael
AU - Bianchi, Luciana
AU - Barlow, Tom A.
AU - Donas, Jose
AU - Forster, Karl
AU - Friedman, Peter G.
AU - Heckman, Timothy M.
AU - Jelinsky, Patrick N.
AU - Malina, Roger F.
AU - Martin, D. Christopher
AU - Milliard, Bruno
AU - Morrissey, Patrick
AU - Neff, Susan G.
AU - Schiminovich, David
AU - Small, Todd
AU - Szalay, Alex S.
AU - Wyder, Ted K.
PY - 2005/1/20
Y1 - 2005/1/20
N2 - The NASA Galaxy Evolution Explorer (GALEX) satellite has obtained simultaneous near-ultraviolet (NUV) and far-ultraviolet (FUV) light curves of the ROTSE-I Catalog RR Lyrae type ab variable star J143753.84+ 345924.8. A series of 38 GALEX Deep Imaging Survey observations well distributed in phase within the star's 0.56432 day period shows an AB = 4.9 mag variation in the FUV (1350-1750 Å) band and an AB = 1.8 mag variation in the NUV (1750-2750 A) band, compared with only a 0.8 mag variation in the broad, unfiltered ROTSE-I (≈4500-10,000 Å) band. These GALEX UV observations are the first to reveal a large RR Lyrae amplitude variation at wavelengths below 1800 A. We compare the GALEX and ROTSE-I observations to predictions made by recent Kurucz stellar atmosphere models. We use published physical parameters for the comparable period (0.57433 days), well-observed RR Lyrae star WY Antliae to compute predicted FUV, NUV, and ROTSE-I light curves for J143753.84+345924.8. The observed light curves agree with the Kurucz predictions for [Fe/H] = -1.25 to within AB = 0.2 mag in the GALEX NUV and ROTSE-I bands and to within 0.5 mag in the FUV. At all metallicities between solar and 1/100 solar, the Kurucz models predict 6-8 mag of variation at wavelengths between 1000 and 1700 Å. Other variable stars with similar temperature variations, such as Cepheids, should also have large-amplitude FUV light curves, observable during the ongoing GALEX imaging surveys.
AB - The NASA Galaxy Evolution Explorer (GALEX) satellite has obtained simultaneous near-ultraviolet (NUV) and far-ultraviolet (FUV) light curves of the ROTSE-I Catalog RR Lyrae type ab variable star J143753.84+ 345924.8. A series of 38 GALEX Deep Imaging Survey observations well distributed in phase within the star's 0.56432 day period shows an AB = 4.9 mag variation in the FUV (1350-1750 Å) band and an AB = 1.8 mag variation in the NUV (1750-2750 A) band, compared with only a 0.8 mag variation in the broad, unfiltered ROTSE-I (≈4500-10,000 Å) band. These GALEX UV observations are the first to reveal a large RR Lyrae amplitude variation at wavelengths below 1800 A. We compare the GALEX and ROTSE-I observations to predictions made by recent Kurucz stellar atmosphere models. We use published physical parameters for the comparable period (0.57433 days), well-observed RR Lyrae star WY Antliae to compute predicted FUV, NUV, and ROTSE-I light curves for J143753.84+345924.8. The observed light curves agree with the Kurucz predictions for [Fe/H] = -1.25 to within AB = 0.2 mag in the GALEX NUV and ROTSE-I bands and to within 0.5 mag in the FUV. At all metallicities between solar and 1/100 solar, the Kurucz models predict 6-8 mag of variation at wavelengths between 1000 and 1700 Å. Other variable stars with similar temperature variations, such as Cepheids, should also have large-amplitude FUV light curves, observable during the ongoing GALEX imaging surveys.
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U2 - 10.1086/422391
DO - 10.1086/422391
M3 - Article
AN - SCOPUS:20044374170
VL - 619
SP - L123-L126
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1 II
ER -