Results 121 to 130 of about 173,010 (211)

The Factory and the Beehive. V. Chromospheric and Coronal Activity and Its Dependence on Rotation in Praesepe and the Hyades

The Astrophysical Journal
Low-mass (≲1.2 M _⊙ ) main-sequence stars lose angular momentum over time, leading to a decrease in their magnetic activity. The details of this rotation–activity relation remain poorly understood, however.
Alejandro Núñez, Marcel A. Agüeros, Jason L. Curtis, Kevin R. Covey, Stephanie T. Douglas, Sabine R. Chu, Stanislav DeLaurentiis, Minzhi (Luna) Wang, Jeremy J. Drake   +8 more
doaj   +1 more source

Red Supergiant Mass Loss and Mass-Loss Rates

Galaxies
This review discusses the causes, nature, importance and observational evidence of mass loss by red supergiants. It arrives at the perception that mass loss finds its origin in the gravity which makes the star a star in the first place, and is a ...
Jacco Th. van Loon
doaj   +1 more source

Temperature distribution in a stellar atmosphere diagnostic basis [PDF]

A stellar chromosphere is considered a region where the temperature increases outward and where the temperature structure of the gas controls the shape of the spectral lines.
Jefferies, J. T., Morrison, N. D.
core   +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

Crowning the Queen: Membership, Age, Rotation, and Activity for the Open Cluster Coma Berenices

The Astrophysical Journal
Despite being only 85 pc away, the open cluster Coma Berenices (Coma Ber) has not been extensively studied. This is due in part to its sparseness and low proper motion, which together made Coma Ber’s membership challenging to establish.
M. A. Agüeros, J. L. Curtis, A. Núñez, C. Burhenne, P. Rothstein, B. J. Shaham, K. Singh, P. Bergeron, M. Kilic, K. R. Covey, S. T. Douglas   +10 more
doaj   +1 more source

Betelgeuse, the Prototypical Red Supergiant

Galaxies
The behavior of the bright red supergiant, Betelgeuse, is described with results principally from the past 6 years. The review includes imaging, photometry, and spectroscopy to record the Great Dimming of 2019–2020.
Andrea K. Dupree, Miguel Montargès
doaj   +1 more source

Search for white dwarf companions of cool stars with peculiar element abundances [PDF]

A search for a white dwarf companions of cool stars with peculiar element abundances was undertaken. One additional star the xi Cet, was found with a white dwarf companion.
Boehm-Vitense, E.
core   +1 more source

Magnetic reconnection in partially ionized plasmas. [PDF]

Proc Math Phys Eng Sci, 2020
Ni L, Ji H, Murphy NA, Jara-Almonte J.
europepmc   +1 more source

Progress in semi-empirical modelling of main-sequence stellar chromospheres [PDF]

, 1996
E. R. Houdebine
openalex   +1 more source

FUMES. IV. Optical and Far-ultraviolet Spectra of a Flare on the M Dwarf GJ 4334

The Astronomical Journal
On 2017 September 20, we observed GJ 4334, an M5V dwarf rotating with a period of 23.5 days, simultaneously with both the Space Telescope Imaging Spectrograph aboard Hubble (1160–1710 Å) and the Dual Imaging Spectrograph mounted on the 3.5 m telescope at
Girish M. Duvvuri, J. Sebastian Pineda, Aylin García Soto, Zachory K. Berta-Thompson, Allison Youngblood, Kevin France, Elisabeth R. Newton, Keivan G. Stassun   +7 more
doaj   +1 more source