Large-amplitude ultraviolet variations in the RR Lyrae star ROTSE-I J143753.84+345924.8

Jonathan M. Wheatley, Barry Y. Welsh, Oswald H.W. Siegmund, Yong Ik Byun, Y. Sukyoung, Young Wook Lee, Barry F. Madore, Maurice Viton, R. Michael Rich, Luciana Bianchi, Tom A. Barlow, Jose Donas, Karl Forster, Peter G. Friedman, Timothy M. Heckman, Patrick N. Jelinsky, Roger F. Malina, D. Christopher Martin, Bruno Milliard, Patrick MorrisseySusan G. Neff, David Schiminovich, Todd Small, Alex S. Szalay, Ted K. Wyder

Research output: Contribution to journalArticle

15 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)L123-L126
JournalAstrophysical Journal
Issue number1 II
Publication statusPublished - 2005 Jan 20

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Large-amplitude ultraviolet variations in the RR Lyrae star ROTSE-I J143753.84+345924.8'. Together they form a unique fingerprint.

  • Cite this

    Wheatley, J. M., Welsh, B. Y., Siegmund, O. H. W., Byun, Y. I., Sukyoung, Y., Lee, Y. W., Madore, B. F., Viton, M., Rich, R. M., Bianchi, L., Barlow, T. A., Donas, J., Forster, K., Friedman, P. G., Heckman, T. M., Jelinsky, P. N., Malina, R. F., Martin, D. C., Milliard, B., ... Wyder, T. K. (2005). Large-amplitude ultraviolet variations in the RR Lyrae star ROTSE-I J143753.84+345924.8. Astrophysical Journal, 619(1 II), L123-L126.