Open AccessSDSS J160043.6+074802.9: a very rapid sdO pulsator
Author(s) -
Woudt P. A.,
Kilkenny D.,
Zietsman E.,
Warner B.,
Loaring N. S.,
Copley C.,
Kniazev A.,
Väisänen P.,
Still M.,
Stobie R. S.,
Burgh E. B.,
Nordsieck K. H.,
Percival J. W.,
O'Donoghue D.,
Buckley D. A. H.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10788.x
Subject(s) - physics , astrophysics , sky , amplitude , telescope , astronomy , binary number , optics , arithmetic , mathematics
We report the serendipitous discovery of the Sloan Digital Sky Survey (SDSS) star SDSS J160043.6+074802.9 to be a very rapid pulsator. The variation is dominated by a frequency near 8380 μHz (period = 119.33 s) with a large amplitude (0.04 mag) and its first harmonic at 16760 μHz (59.66 s; 0.005 mag). In between these frequencies, we find at least another eight variations with periods between 62 and 118 s and amplitudes between about 0.007 and 0.003 mag; weaker oscillations might also be present. Preliminary spectrograms from the performance verification phase of the Southern African Large Telescope indicate that SDSS J160043.6+074802.9 is a spectroscopic binary consisting of an sdO star and a late‐type main‐sequence companion. This makes it the first unambiguous detection of such an sdO star to pulsate, and certainly the first found to exhibit multifrequency variations.