Results 11 to 20 of about 7,783 (257)
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
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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
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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
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The stellar activity‐rotation relationship [PDF]
Astronomische Nachrichten, 2013 AbstractUsing a new catalog of 824 solar and late‐type stars with measured X‐ray luminosities and rotation periods we have studied the relationship between rotation and stellar activity that is believed to be a probe of the underlying stellar dynamo. Using an unbiased subset of the sample we calculate the power law slope of the unsaturated regime of ...
Wright, Nicholas J. +3 more
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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
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Symposium - International Astronomical Union, 1986 We have been monitoring the CaII H and K emission in late-type giant stars using the Mt Wilson 60-inch telescope. It is a continuation of work that Olin Wilson began almost 20 years ago. As a result not only have starspot cycles been detected (equivalent to the solar sunspot cycle), but rotation periods have now been measured.
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Analysis of Solar-like X-class Flare on Wolf 359 Observed Simultaneously with TESS and XMM-Newton
The Astrophysical Journal, 2023 We present an analysis of a flare on the Wolf 359 star based on simultaneous observations of Transiting Exoplanet Survey Satellite and XMM-Newton. A stellar flare with energy comparable to an X-class solar flare is analyzed on this star for the first ...
M. Pietras +5 more
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The Astrophysical Journal Supplement Series, 2022 Stellar parameters and magnetic activity are important for the understanding of stellar physics and dynamo theory. We have used LAMOST spectroscopic surveys to study stellar parameters and magnetic activity properties of TESS objects.
Li-yun Zhang +6 more
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Solar and Stellar Flares: Frequency, Active Regions, and Stellar Dynamo
The Astrophysical Journal, 2022 Abstract We demonstrate that for weak flares the dependence of their frequency occurrence on spottedness can be rather weak. The fact is that such flares can occur in both small and large active regions. At the same time, powerful large flares of classes M and X occur much more often in large active regions. In energy estimates, the mean
M. M. Katsova +3 more
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Space Science Reviews, 2023 AbstractThe magnetic field of the Sun is generated by internal dynamo process with a cyclic period of 11 years or a 22 year magnetic cycle. The signatures of the Sun’s magnetic cycle are observed in the different layers of its atmosphere and in its internal layers.
Jeffers, Sandra V. +2 more
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