Results 81 to 90 of about 164 (131)

Role of Nonthermal Processes in the Quiescent and Active Millimeter Spectrum of a Young M Dwarf

The Astrophysical Journal
Millimeter (mm) emission from F-M dwarfs (cool stars) primarily traces chromospheric activity, with thermal emission thought to dominate in quiescence. Despite the high chromospheric activity, the quiescent mm spectral fluence (mm- S ( ν )) of young (1 ...
Atul Mohan, Peter H. Hauschildt, Birgit Fuhrmeister, Surajit Mondal, Vladimir Airapetian, Sven Wedemeyer   +5 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

87th Annual Meeting of the Meteoritical Society 2025: Abstracts

Meteoritics &Planetary Science, Volume 60, Issue S1, Page 30-350, August 2025.
wiley   +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

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

Potential Chromospheric Evaporation in the M Dwarf’s Flare Triggered by Einstein Probe Mission

The Astronomical Journal
Although flares from late-type main-sequence stars have been frequently detected in the multiwavelength, the associated dynamical process has been rarely reported so far.
J. Wang, X. Mao, C. Gao, H. Y. Liu, H. L. Li, H. W. Pan, C. Wu, Y. Liu, G. W. Li, L. P. Xin, S. Jin, D. W. Xu, E. W. Liang, W. M. Yuan, J. Y. Wei   +14 more
doaj   +1 more source

The Impact of Dust/Gas Ratios on Chromospheric Activity in Red Giant and Supergiant Stars. [PDF]

Proc Int Astron Union, 2018
Carpenter KG, Rau G.
europepmc   +1 more source

HST-STIS Spectra of Antares (α Scorpii: M1.5 Iab)—Type II Supernova Progenitor and Betelgeuse’s Chromospheric Twin

The Astrophysical Journal
We present the first Hubble Space Telescope - Space Telescope Imaging Spectrograph (HST-STIS) far-ultraviolet (FUV) and near-ultraviolet (NUV) high-resolution spectra of the red supergiant (RSG) Antares (M1.5 Iab), isolated from its long-period B-star ...
Graham M. Harper, Thomas R. Ayres, Keiichi Ohnaka, Edward F. Guinan, Curtis DeWitt   +4 more
doaj   +1 more source

Mind the Gap. II. The Near-UV Fluxes of M Dwarfs

The Astronomical Journal
Because of the continuous variations in mass, metallicity, and opacity, dwarf stars are distributed along the main sequence on optical and near-IR color–magnitude diagrams following a smooth polynomial.
Wei-Chun Jao, Allison Youngblood
doaj   +1 more source