KIC 10449976: discovery of an extreme-helium subdwarf in the Kepler   field
  Optical spectroscopy of the blue star KIC 10449976 shows that it is an extremely helium-rich subdwarf with effective temperature T=40000+/-300 K and surface gravity log g=5.3+/-0.1. Radial-velocity measurements over a five-day timescale show an upper variability limit of ~50+/-20 km/s. Kepler photometry of KIC 10449976 in both long and short cadence modes shows evidence for a periodic modulation on a timescale of ~3.9 days. We have examined the possibility that this modulation is not astrophysical but conclude it is most likely real. We discuss whether the modulation could be caused by a low-mass companion, by stellar pulsations, or by spots. The identification of any one of these as cause has important consequences for understanding the origin of helium-rich subdwarfs. 
C.S. Jeffery (1), G. Ramsay (1), N. Naslim (1), R. Carrera (2,3), S.   Greiss (4), T. Barclay (5,6), R. Karjalainen (7), A. ...
astro-ph.SR