Coordinated Ginga, IUE, and VLA observations of stellar activity in Sigma(2) Coronae Borealis
1992; IOP Publishing; Volume: 391; Linguagem: Inglês
10.1086/171386
ISSN1538-4357
AutoresRobert A. Stern, Yuusuke Uchida, F. Walter, O. Vilhu, Diana Hannikainen, Alexander Brown, Anthony Veale, B. M. Haisch,
Tópico(s)Solar and Space Plasma Dynamics
Resumoview Abstract Citations (25) References (58) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Coordinated Ginga, IUE, and VLA Observations of Stellar Activity in sigma 2 Coronae Borealis Stern, R. A. ; Uchida, Y. ; Walter, F. ; Vilhu, O. ; Hannikainen, D. ; Brown, A. ; Veale, A. ; Haisch, B. M. Abstract Observations of the active cool star binary system Sigma(2) Corona Borealis with the Large Area Counters on the Ginga X-ray satellite over 2.5 d, or about two orbital periods, are reported. Throughout the observations, Sigma(2) CrB exhibited X-ray variability on time scales ranging from tens of minutes to hours. The X-ray light curve shows evidence of flaring during the course of the observations. The summed X-ray pulse height spectrum from flaring events compared with similar spectra from quiescent periods indicates an increase in coronal temperature. Periodogram analysis of the entire X-ray light curve shows a possible periodicity at about 0.40-0.44 d, with no strong signal at the orbital period or 1/2 of the orbital period. Coordinated multiwavelength observations of IUE and the VLA indicate both UV and microwave flaring during one X-ray outburst. The quiescent microwave spectrum is not consistent with a thermal gyrosynchrotron process; nonthermal gyrosynchrotron radiation is argued to be the most likely emission process. Publication: The Astrophysical Journal Pub Date: June 1992 DOI: 10.1086/171386 Bibcode: 1992ApJ...391..760S Keywords: Cool Stars; Iue; Light Curve; Stellar Activity; X Ray Astronomy; X Ray Binaries; Coronas; Cosmic X Rays; Ginga Satellite; Ultraviolet Spectra; Astrophysics full text sources ADS | data products SIMBAD (11) MAST (1) INES (1)
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