Einstein Observatory coronal temperatures of late-type stars

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169525· OSTI ID:5995592

Schmitt, J H.M.M.; Collura, A; Sciortino, S; Vaiana, G S; Harnden, Jr, F R ^[1]

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1. Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.) CNR, Istituto per le Applicazioni Interdisciplinari della Fisica, Palermo (Italy) Palermo, Osservatorio Astronomico (Italy) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA)

The results are presented of a survey of the coronal temperatures of late-type stars using the Einstein Observatory IPC. The spectral analysis shows that the frequently found one- and two-temperature descriptions are mainly influenced by the SNR of the data and that models using continuous emission measure distributions can provide equally adequate and physically more meaningful and more plausible descriptions. Intrinsic differences in differential emission measure distributions are found for four groups of stars. M dwarfs generally show evidence for high-temperature gas in conjunction with lower-temperature material, while main-sequence stars of types F and G have the high-temperature component either absent or very weak. Very hot coronae without the lower-temperature component appearing in dwarf stars are evident in most of the giant stars studied. RS CVn systems show evidence for extremely hot coronae, sometimes with no accompanying lower-temperature material. 51 refs.

• OSTI ID: 5995592
• Journal Information: Astrophysical Journal; (USA), Vol. 365; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
STELLAR CORONAE
TEMPERATURE MEASUREMENT
X-RAY SPECTRA
COSMIC X-RAY SOURCES
DWARF STARS
GIANT STARS
MAIN SEQUENCE STARS
PROPORTIONAL COUNTERS
SIGNAL-TO-NOISE RATIO
SPECTRA
STAR MODELS
ATMOSPHERES
COSMIC RAY SOURCES
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
RADIATION DETECTORS
STARS
STELLAR ATMOSPHERES
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources