Results 1 to 10 of about 169 (167)
Coronae of stars with supersolar elemental abundances [PDF]
Astronomy and Astrophysics, 2015 Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the First Ionization Potential (FIP). This study focuses on the coronal composition of stars with super-solar photospheric abundances.
Ehud Béhar +2 more
exaly +3 more sources
Symposium - International Astronomical Union, 2004 We present preliminary results of grating observations of YY Mensae and V824 Arae by Chandra and XMM-Newton. Spectral features are presented in the context of the emission measure distributions, the coronal abundances, and plasma electron densities.
Audard, M. +8 more
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A Census of Stars and Disks in Corona Australis*
The Astronomical Journal, 2022 Abstract We have performed a census of the young stellar populations near the Corona Australis molecular cloud using photometric and kinematic data from several sources, particularly Gaia EDR3, and spectroscopy of hundreds of candidate members.
T. L. Esplin, K. L. Luhman
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Pulsations of the R Coronae Borealis stars [PDF]
Space Science Reviews, 1980 AbstractThe radial pulsations of very luminous, low-mass models (L/M ˜ 104, solar units), which are possible representatives of the R CrB stars, have been examined. These pulsations are extremely nonadia–batic. We find that there are in some cases at least one extra (“strange”) mode which makes interpretation difficult.
Cox, J. P. +5 more
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R Coronae Borealis Stars [PDF]
International Astronomical Union Colloquium, 2004 AbstractIn the last ten years a significant step forward has been made toward a better understanding of the evolutionary status and unusual nature of the R Coronae Borealis (RCB) stars, a rare class of hydrogen-poor and carbon-rich variable stars. More detailed abundance analyses of the majority of RCB stars, and objects related to them, have become ...
Ljiljana Skuljan, Peter L. Cottrell
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Stellar-winds and coronas in cool stars [PDF]
International Astronomical Union Colloquium, 1980 AbstractRecent observational and theoretical results are reviewed that pertain to the presence and characteristics of stellar coronae and winds in late-type stars. It is found that stars - principally dwarfs - exist with “hot” coronae similar to the Sun with thermally driven winds.
A.K. Dupree, L. Hartmann
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What Are the Hot R Coronae Borealis Stars? [PDF]
The Astronomical Journal, 2002 We investigate the evolutionary status of four stars: V348 Sgr, DY Cen and MV Sgr in the Galaxy and HV 2671 in the LMC. These stars have in common random deep declines in visual brightness which are characteristic for R Coronae Borealis (RCB) stars. RCB stars are typically cool, hydrogen deficient supergiants.
De Marco, Orsola +5 more
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A Hot Corona Model for O-Stars and WR Stars [PDF]
Symposium - International Astronomical Union, 1982 Atmospheric models are presented for the outer layers of hot stars, O, of and Wolf-Rayet stars. The model is a two component hybrid model, consisting of a rapidly expanding component and a slower component. for the rapidly expanding component the energy sources are radiation pressure, a deposit of internally generated and stored energy, and radiation ...
W. Robbrecht, C. de Loore, G. Olson
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Evolving R Coronae Borealis stars with mesa [PDF]
Monthly Notices of the Royal Astronomical Society, 2019 ABSTRACT The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich supergiants. They undergo extreme, irregular declines in brightness of many magnitudes due to the formation of thick clouds of carbon dust. It is thought that RCB stars result from the mergers of CO/He white dwarf (WD) binaries.
Dominic C Marcello +4 more
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