RAPIDLY ROTATING, X-RAY BRIGHT STARS IN THE KEPLER FIELD

Journal Article · Tue Nov 01 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/831/1/27· OSTI ID:22667276

Howell, Steve B. ^[1]; Mason, Elena ^[2]; Boyd, Patricia; Smith, Krista Lynne ^[3]; Gelino, Dawn M. ^[4]

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1. NASA Ames Research Center, Moffett Field, CA 94035 (United States)
2. INAF-OATS, Via G. B. Tiepolo 11, I-34143, Trieste (Italy)
3. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
4. NASA Exoplanet Science Institute, Caltech, Pasadena, CA 91125 (United States)

We present Kepler light curves and optical spectroscopy of twenty X-ray bright stars located in the Kepler field of view. The stars, spectral type F-K, show evidence for rapid rotation including chromospheric activity 100 times or more above the Sun at maximum and flaring behavior in their light curves. Eighteen of our objects appear to be (sub)giants and may belong to the class of FK Com variables, which are evolved rapidly spinning single stars with no excretion disk and high levels of chromospheric activity. Such stars are rare and are likely the result of W UMa binary mergers, a process believed to produce the FK Com class of variable and their descendants. The FK Com stage, including the presence of an excretion disk, is short lived but leads to longer-lived stages consisting of single, rapidly rotating evolved (sub)giants with high levels of stellar activity.

• OSTI ID: 22667276
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 831; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ROTATION
SPECTROSCOPY
STAR EVOLUTION
STELLAR ACTIVITY
STELLAR FLARES
SUN
VISIBLE RADIATION
X RADIATION