Results 91 to 100 of about 151,165 (141)

OUTER LAYERS OF A CARBON STAR - THE VIEW FROM THE HUBBLE-SPACE-TELESCOPE

, 1995
To advance our understanding of the relationship between stellar chromospheres and mass loss, which is a common property of carbon stars and other asymptotic giant branch stars, we have obtained ultraviolet spectra of the nearby N-type carbon star UU ...
ERIKSSON, Kjell, AVRETT, EH, JUDGE, PD, QUERCI, F, CARPENTER, KG, GUSTAFSSON, Bengt, LINSKY, JL, ROBINSON, RD, ENSMAN, LM, JOHNSON, HR,, ALEXANDER, DR, LUTTERMOSER, DG, WING, RF, QUERCI, M, JORGENSEN, UG, BROWN, A   +15 more
core  

Evidence for stellar chromospheres presented by ultraviolet observations of the sun and stars [PDF]

, 1973
Observations of emission lines in stellar sources in the ultraviolet region of the spectrum show P Cygni-like evidence of mass outflow as well as many ultraviolet emission lines which cannot be interpreted wholly in terms of geometric effects.
Doherty, L.
core  

Fallback-triggered Reconnection Drives Coronal Mass Ejections on II Pegasi

The Astrophysical Journal Letters
Stellar coronal mass ejections (CMEs) play key roles in stellar evolution and planetary habitability. On the Sun, CMEs typically originate from preexisting prominences or filaments, while materials condensed via the evaporation–condensation process have ...
Dongtao Cao, Shenghong Gu
doaj   +1 more source

ON THE VALIDITY OF ACOUSTICALLY HEATED CHROMOSPHERE MODELS

, 2020
Theoretical models of solar and stellar chromospheres heated by acoustic waves have so far been constructed by using time-dependent, one-dimensional, radiation-hydrodynamic numerical codes that are based on the approximation of plane-parallel geometry ...
W Kalkofen, W Rammacher, Z E Musielak, P Ulmschneider   +3 more
core  

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

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

The California Legacy Survey. V. Chromospheric Activity Cycles in Main-sequence Stars

The Astrophysical Journal Supplement Series
We present optical spectroscopy of 710 solar neighborhood stars collected over 20 years to catalog chromospheric activity and search for stellar activity cycles.
Howard Isaacson, Andrew W. Howard, Benjamin Fulton, Erik A. Petigura, Lauren M. Weiss, Stephen R. Kane, Brad Carter, Corey Beard, Steven Giacalone, Judah Van Zandt, Joseph M. Akana Murphy, Fei Dai, Ashley Chontos, Alex S. Polanski, Malena Rice, Jack Lubin, Casey Brinkman, Ryan A. Rubenzahl, Sarah Blunt, Samuel W. Yee, Mason G. MacDougall, Paul A. Dalba, Dakotah Tyler, Aida Behmard, Isabel Angelo, Daria Pidhorodetska, Andrew W. Mayo, Rae Holcomb, Emma V. Turtelboom, Michelle L. Hill, Luke G. Bouma, Jingwen Zhang, Ian J. M. Crossfield, Nicholas Saunders   +33 more
doaj   +1 more source

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

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

Exploration of the Outer Envelope of the K-giant Star Beta Cet

The Astrophysical Journal
Investigating the atmospheres of giants and supergiants is critical to expanding our knowledge of stellar life cycles, galaxy formation, and the origin of material that forms exoplanets.
Krister E. Nielsen, Gioia Rau, Kenneth G. Carpenter   +2 more
doaj   +1 more source