Results 11 to 20 of about 6,190,013 (295)
Revisiting the HD 21749 planetary system with stellar activity modelling [PDF]
, 2021 HD 21749 is a bright (V = 8.1 mag) K dwarf at 16 pc known to host an inner terrestrial planet HD 21749c as well as an outer sub-Neptune HD 21749b, both delivered by Transiting Exoplanet Survey Satellite (TESS).
Flowers, Erin +28 more
core +1 more source
Physical Properties of Radio Stars Based on LAMOST Spectral Survey
Universe, 2022 Radio emission has been detected for all types of stars in the Hertzsprung Russell diagram. Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low and medium-resolution spectroscopic surveys provide a good opportunity to obtain the ...
Liyun Zhang +6 more
doaj +1 more source
Is Core Angular Momentum Key to the Giant Dynamo?
Universe, 2022 The pros and cons of core angular momentum dissipation into the convective envelopes of giants as a driver of giant activity is discussed in face of the observational evidence, which points to two ”magnetic strips“, in the HRD, where in the first, at the
Klaus-Peter Schröder +1 more
doaj +1 more source
Magnetic Activity of Different Types of Variable Stars Observed by TESS Mission
Universe, 2023 The investigation of the magnetic activity of different types of variable stars holds significant implications for our understanding of the physical processes and evolution of stars.
Ming Zhong +3 more
doaj +1 more source
Spots and Flares in Hot Main Sequence Stars Observed by Kepler, K2, and TESS
Frontiers in Astronomy and Space Sciences, 2021 About 22,000 Kepler stars, 7,000 K2 stars, and nearly 60,000 TESS stars from sectors 1–24 have been classified according to variability type. A large proportion of stars of all spectral types appear to have periods in their light curves consistent with ...
Luis A. Balona
doaj +1 more source
A Stringent Test of Magnetic Models of Stellar Evolution
Galaxies, 2021 Main-sequence stars with convective envelopes often appear larger and cooler than predicted by standard models of stellar evolution for their measured masses. This is believed to be caused by stellar activity.
Guillermo Torres +3 more
doaj +1 more source
Multiverse Predictions for Habitability: Stellar and Atmospheric Habitability
Universe, 2022 Stellar activity and planetary atmospheric properties have the potential to strongly influence habitability. To date, neither have been adequately studied in the multiverse context, so there has been no assessment of how these effects impact the ...
McCullen Sandora +3 more
doaj +1 more source
STELLAR ACTIVITY IN THE BROADBAND ULTRAVIOLET [PDF]
The Astronomical Journal, 2011 The completion of the GALEX All-Sky Survey in the ultraviolet allows activity measurements to be acquired for many more stars than is possible with the limited sensitivity of ROSAT or the limited sky coverage of Chandra, XMM, or spectroscopic surveys for line emission in the optical or ultraviolet.
Findeisen, K. +2 more
openaire +3 more sources
THE STELLAR-ACTIVITY-ROTATION RELATIONSHIP AND THE EVOLUTION OF STELLAR DYNAMOS [PDF]
The Astrophysical Journal, 2011 We present a sample of 824 solar and late-type stars with X-ray luminosities and rotation periods. This is used to study the relationship between rotation and stellar activity and derive a new estimate of the convective turnover time. From an unbiased subset of this sample the power law slope of the unsaturated regime, L_X / L_bol = Ro^β, is fit as β= -
Wright, Nicholas J. +3 more
openaire +2 more sources
On the gamma-activity of stellar flares [PDF]
Symposium - International Astronomical Union, 1990 The principal possibility of γ-ray manifestation of stellar flares in the framework of pinch-model is shown. Validity of assumption that, γ-bursts are connected with magnetically active dwarfs (MAD) is discussed.
H. A. Harutyunian, V. S. Hayrapetyan
openaire +1 more source