Einstein detection of x-rays from the alpha Centauri system

Journal Article · Mon Feb 01 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159629· OSTI ID:5170236

Golub, L; Harnden, Jr, F R; Pallavicini, R; Rosner, R; Vaiana, G S

We report detection of quiescent x-ray emission from the stellar components of the ..cap alpha.. Cen system: ..cap alpha.. Cen A (G2 V) and ..cap alpha.. Cen B (K1 V). Contrary to previous theoretical expectations (e.g., Mewe), both stars are x-ray emitters and at about the same level: L/sub x/ = 1.2 x 10/sup 27/ and 2.8 x 10/sup 27/ ergs s /sup -1/ for A and B, respectively; the sum of these values is in agreement with the emission level previously reported for ..cap alpha.. Cen by Nugent and Garmire. Comparison with previous chromospheric and transition region measurements indicates that ..cap alpha.. Cen A and B may have changed in relative strength in recent years. The coronal temperature of the combined Cen AB source, which is dominated (..mu..2/3 of the total) by the K star, is (2.1 +- 0.4) x 10/sup 6/ K, similar to that of the average solar corona; this value is not consistent with the estimate of 5 x 10/sup 5/ K quoted by Nugent and Garmire. The applicability of coronal loop models and the conclusions which can be drawn on the basis of such models are discussed, using the Sun and ..cap alpha.. Cen stars as examples.

• Research Organization: Harvard-Smithsonian Center for Astrophysics
• OSTI ID: 5170236
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 253:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640103 -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BINARY STARS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
MAIN SEQUENCE STARS
MATHEMATICAL MODELS
PLASMA
SPECTRA
STAR MODELS
STARS
STELLAR ATMOSPHERES
X-RAY SPECTRA