A comparison of the near-ultraviolet continuum and chromospheric emission line fluxes of the late-type giant stars

1990 ◽  
Vol 164 (2) ◽  
pp. 263-276
Author(s):  
K�muran Avcioglu ◽  
M. T�rker �zkan ◽  
H. H�seyin Mentese
Keyword(s):  
Emission Line ◽  
Late Type ◽  
Ultraviolet Continuum ◽  
Giant Stars ◽  
Near Ultraviolet ◽  
Chromospheric Emission ◽  
Type Giant

scholarly journals The Chromospheres of Carbon Stars

2000 ◽  
Vol 177 ◽  
pp. 105-114 ◽  
Author(s):  
Donald G. Luttermoser
Keyword(s):  
High Resolution ◽  
Carbon Star ◽  
High Dispersion ◽  
Late Type ◽  
Carbon Stars ◽  
Giant Stars ◽  
Show Evidence ◽  
Chromospheric Emission ◽  
Type Giant ◽  
Low Dispersion

Most oxygen-rich late-type giant stars show evidence for chromospheres in their visual spectra (e.g. Ca ii H & K emission features). Cool (i.e. N-type) non-Mira carbon stars, however, have never been observed to have chromospheric emission in their Ca ii H & K lines. However, faint Mg ii h & k lines were detected in emission in low-dispersion IUE spectra of the brightest cool carbon stars in the early 1980s. May 1984 saw the first (and only) successful high-dispersion IUE spectrum taken of a cool carbon star, TX Psc (N0; C6,2). Armed with this high-dispersion spectrum, as well as low-dispersion IUE and ground-based spectra, Luttermoser et al. (1989) made the first detailed attempt to semiempirically model the chromosphere of a cool carbon star. This model was successful in reproducing the Mg ii lines, but it was not well constrained due to the lack of other observed high-resolution chromospheric profiles for comparison. Modeling carbon star chromospheres can now be addressed more accurately with HST/GHRS high-resolution spectra. New fluoresced emission features have been discovered in the GHRS spectra of carbon stars that are not present in their oxygen-rich counterparts.

Magnesium emission variability among late-type giant stars

1982 ◽  
Vol 253 ◽  
pp. 716 ◽  
Author(s):  
D. J. Mullan ◽  
R. E. Stencel
Keyword(s):  
Late Type ◽  
Giant Stars ◽  
Type Giant

scholarly journals Stellar activity

1986 ◽  
Vol 118 ◽  
pp. 283-283
Author(s):  
D. K. Duncan
Keyword(s):  
Sunspot Cycle ◽  
Late Type ◽  
Stellar Activity ◽  
Giant Stars ◽  
Rotation Periods ◽  
Type Giant

We have been monitoring the CaII H and K emission in late-type giant stars using the Mt Wilson 60-inch telescope. It is a continuation of work that Olin Wilson began almost 20 years ago. As a result not only have starspot cycles been detected (equivalent to the solar sunspot cycle), but rotation periods have now been measured.

Luminosity and Temperature from Near-Infrared Spectra of Late-Type Giant Stars

1997 ◽  
Vol 113 ◽  
pp. 1411 ◽  
Author(s):  
S. V. Ramirez ◽  
D. L. Depoy ◽  
Jay A. Frogel ◽  
K. Sellgren ◽  
R. D. Blum
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Late Type ◽  
Giant Stars ◽  
Near Infrared Spectra ◽  
Type Giant

The Near-Ultraviolet Continuum of Late-Type Stars

2000 ◽  
Vol 119 (5) ◽  
pp. 2445-2454 ◽  
Author(s):  
Carlos Allende Prieto ◽  
David L. Lambert
Keyword(s):  
Late Type ◽  
Ultraviolet Continuum ◽  
Near Ultraviolet

scholarly journals Acoustic wave driven mass loss in late-type giant stars

1987 ◽  
Vol 122 ◽  
pp. 325-326 ◽  
Author(s):  
M. Cuntz ◽  
L. Hartmann ◽  
P. Ulmschneider
Keyword(s):  
Acoustic Wave ◽  
Mass Loss ◽  
Wave Field ◽  
Wave Energy ◽  
Acoustic Waves ◽  
Late Type ◽  
Large Wave ◽  
Giant Stars ◽  
Wave Energy Flux ◽  
Type Giant

Mass loss generated by radiatively damped acoustic waves is investigated. We find that a persistent wave energy flux leads to extended chromospheres. Mass loss is quite likely produced if the wave field retains a transient character and if large wave periods are used.

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