Results 11 to 20 of about 7,344 (264)
Stellar Chromospheric Activity [PDF]
Living Reviews in Solar Physics, 2008 The Sun, stars similar to it, and many rather dissimilar to it, have chromospheres, regions classically viewed as lying above the brilliant photosphere and characterized by a positive temperature gradient and a marked departure from radiative equilibrium.
Hall Jeffrey C.
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Stellar magnetic activity and exoplanets [PDF]
EPJ Web of Conferences, 2017 It has been proposed that magnetic activity could be enhanced due to interactions between close-in massive planets and their host stars. In this article, I present a brief overview of the connection between stellar magnetic activity and exoplanets ...
Vidotto A.A.
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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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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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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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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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, 2021 From an observational standpoint, stellar activity poses a critical challenge to exoplanet science, as it inhibits the detection of planets and the precise measurement of their parameters. Radial velocity and transit searches revealed a significant fraction of exoplanet hosts is active, and showed the need to fully understand the different facets of ...
Bruno, Giovanni, Deleuil, Magali
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Highlights of Astronomy, 1986 AbstractThe main features of solar and stellar activity cycles are summarized, followed by a discussion of some outstanding observational problems for the future.
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Stellar populations in active galaxies [PDF]
Proceedings of the International Astronomical Union, 2004 To appear in "The Interplay among Black Holes, Stars and ISM in Galactic Nuclei", T. Storchi Bergmann, L.C. Ho & H.R. Schmitt, eds., Proc IAU Symp 222 (Cambridge University Press)
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Asteroseismic stellar activity relations [PDF]
Astronomy & Astrophysics, 2014 5 pages, 4 figures, 2 tables.
Bonanno, A., Corsaro, E., Karoff, C.
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