Results 91 to 100 of about 146,288 (166)

Chromospheres of Coronal Stars [PDF]

, 1996
We summarize the main results obtained from the analysis of ultraviolet emission line profiles of coronal late-type stars observed with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope.
Brian E. Wood, Wood, Brian E., Jeffrey L. Linsky, Linsky, Jeffrey L.   +3 more
core   +1 more source

HWO Target Stars and Systems: A Survey of Archival UV and X-Ray Data

The Astronomical Journal
We assess archival high-energy data for key stars on the Habitable Worlds Observatory (HWO) Target Stars and Systems 2025 list, as stellar radiation is critical to shaping and interpreting planetary atmospheres.
Sarah Peacock, David J. Wilson, Tyler Richey-Yowell, Noah W. Tuchow, Kevin France, José A. Caballero, Riccardo Spinelli, Lía Corrales, Aiden S. Zelakiewicz, Seth Redfield, Keighley Rockcliffe, Allison Youngblood, Cynthia S. Froning, Girish M. Duvvuri, Breanna A. Binder, Natalie R. Hinkel, Eric E. Mamajek   +16 more
doaj   +1 more source

A Possible Stellar Coronal Mass Ejection Event Associated with a Long-duration Optical Flare on the RS CVn-type Star UX Arietis

The Astrophysical Journal
Coronal mass ejections (CMEs) are large-scale eruptions of magnetized plasma from stellar coronae, and they are always accompanied by flares. In this study, we present high-resolution spectroscopic observations of a long-duration optical flare on the RS ...
Dongtao Cao, Shenghong Gu
doaj   +1 more source

Stellar chromospheric and coronal heating by magnetohydrodynamic waves

The Astrophysical Journal, 1981
An investigation is presented on the way in which the generation of magnetohydrodynamic waves by turbulent motions in stellar convection zones depends on the star's effective temperature, surface gravity, and magnetic field strength. It is shown that the emitted Alfven wave flux (and acoustic slow wave flux in a very strong magnetic field) is in ...
openaire   +1 more source

High-pressure transition regions in stellar model chromospheres

The Astrophysical Journal, 1979
The implications of recent ultraviolet observations of stellar transition-region lines for calculations of the Ca II and Mg II resonance lines are investigated. It is found that the adoption of high transition-region pressures for stars with active chromospheres, such as Lambda And and Alpha Aur, can be consistent with observed Ca II fluxes, contrary ...
S. L. Baliunas, E. H. Avrett, L. Hartmann, A. K. Dupree   +3 more
openaire   +1 more source

Galaxy And Mass Assembly (GAMA) : galaxy close pairs, mergers and the future fate of stellar mass [PDF]

, 2014
ASGR acknowledges STFC and SUPA funding that were used to do this work. GAMA is funded by the STFC (UK), the ARC (Australia), the AAO and the participating institutions.We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift
De Propris, R., De Propis, R., T McNaught-Roberts (16161611), Pimbblet, K. A., A Moffett (7731959), Driver, S. P., M S Owers (16161563), Lara-Lopez, M. A., A M Hopkins (16143587), Lopez-Sanchez, Angel R., B W Holwerda (16219943), Jonathan Loveday (4460899), Owers, M. S., R De Propris (16161587), Obreschkow, D., Holwerda, Benne W., M Cluver (16191152), Baldry, I. K., J Bland-Hawthorn (16111139), Davies, L. J. M., Bauer, A. E., E N Taylor (16143620), Brown, M. J. I., A S G Robotham (16143614), M A Lara-Lopez (16161575), A E Bauer (16161566), Hopkins, A. M., E van Kampen (16112642), Brough, S., Loveday, J., McNaught-Roberts, T., I K Baldry (16072595), Moffett, A., Liske, J., Wilkins, S. M., P Norberg (16143575), Holwerda, B. W., Mahajan, S., L S Kelvin (16143602), K Pimbblet (16191149), Penny, S. J., Robotham, A. S. G., van Kampen, E., M Prescott (10000280), M J Drinkwater (16091732), Bland-Hawthorn, J., N K Agius (16219940), Agius, N. K., Prescott, M., M J I Brown (16143632), Cluver, M., Drinkwater, M. J., S J Penny (16219955), Taylor, E. N., Stephen Wilkins (4461910), Lopez-Sanchez, A. R., D Obreschkow (16219952), S Brough (16143590), S Mahajan (16219949), L J M Davies (16219937), Norberg, P., J Liske (7814738), Kelvin, L. S., Pimbblet, K., S P Driver (16143581), A R López-Sánchez (16219946)   +65 more
core   +1 more source

High Lithium Abundance Connection with the Chromospheric Helium in Red Giants: Spectroscopic and Asteroseismic Analyses

The Astrophysical Journal
We present a study of correlations between high Li abundances and strong chromospheric He i λ 10830 absorption-line strengths in Kepler field giant stars.
Anohita Mallick, Christopher Sneden, Bacham E. Reddy, Melike Afşar   +3 more
doaj   +1 more source

THE PRESENT STATE OF WAVE-HEATING THEORIES OF STELLAR CHROMOSPHERES

, 1986
Observational constraints are summarized and the present state of the acoustic and mhd-wave heating theories for chromospheres in early and late-type stars are discussed.
P Ulmschneider
core  

Doppler-shifted Signatures in the Chromospheric Line Profiles of II Pegasi

The Astrophysical Journal
Stellar flares are frequently accompanied by prominence eruptions, coronal mass ejections (CMEs), and other forms of plasma motion. Based on the long-term high-resolution spectroscopic monitoring data set of the RS CVn-type star II Pegasi (II Peg), we ...
Dongtao Cao, Shenghong Gu
doaj   +1 more source

Further Investigation on Chromospheric Activity Patterns of the RS Canum Venaticorum Star V711 Tauri

The Astronomical Journal
We present new long-term spectroscopic observations of the very active RS Canum Venaticorum (RS CVn) star V711 Tauri (V711 Tau), obtained during several observing runs from 2005 to 2021.
Dongtao Cao, Shenghong Gu
doaj   +1 more source