Results 41 to 50 of about 250 (146)

Magnetic activity on the young Sun: A case study of EK Draconis

Astronomy & Astrophysics
Context. Young solar analog stars provide key insights into the early stages of stellar evolution, particularly in terms of magnetic activity and rotation.
Görgei A., Kriskovics L., Vida K., Seli B., Oláh K., Sági P., Bódi A., Järvinen S. P., Strassmeier K. G., Pál A., Kővári Zs.   +10 more
doaj   +1 more source

Doppler imaging combined with high-cadence photometry

Astronomy & Astrophysics
Context. Latitude distribution of stellar magnetic activity is not well constrained by observations, despite its importance for a better understanding of stellar dynamos and their effects on planetary environments. Aims.
Lee S., Bahar E., Şenavcı H. V., Işık E., Ikuta K., Namekata K., Nagata H., Kawauchi K., Omiya M., Izumiura H., Tajitsu A., Sato B., Honda S., Nogami D.   +13 more
doaj   +1 more source

Core-envelope Decoupling Drives Radial Shear Dynamos in Cool Stars

The Astrophysical Journal Letters, 2023
Differential rotation is thought to be responsible for the dynamo process in stars like our Sun, driving magnetic activity and starspots. We report that starspot measurements in the Praesepe open cluster are strongly enhanced only for stars that depart ...
Lyra Cao, Marc H. Pinsonneault, Jennifer L. van Saders   +2 more
doaj   +1 more source

Molecules as magnetic probes of starspots [PDF]

Astronomy & Astrophysics, 2015
Stellar dynamo processes can be explored by measuring the magnetic field. This is usually obtained using the atomic and molecular Zeeman effect in spectral lines. While the atomic Zeeman effect can only access warmer regions, the use of molecular lines is of advantage for studying cool objects.
Afram, N., Berdyugina, S. V.
openaire   +2 more sources

Forward modeling solar spectra onto Doppler images of λ And

Astronomy & Astrophysics
Context. Due to their high chromospheric activity and photometric variability, RS CVn-type binaries are ideal laboratories for studying stellar surface structures and the corresponding stellar activity relations.
Adebali Ö., Pietrow A. G. M.
doaj   +1 more source

Subduction, Stratosphere, Starspots, and Sushi

Eos, 2017
Highlights from AGU’s joint meeting with the Japan Geophysical Union.
Jenny Lunn, Thorsten Becker, Delores Knipp, Andrew Yau, Minghua Zhang   +4 more
openaire   +1 more source

Stellar Flares, Superflares, and Coronal Mass Ejections—Entering the Big Data Era

Universe
Flares, sometimes accompanied by coronal mass ejections (CMEs), are the result of sudden changes in the magnetic field of stars with high energy release through magnetic reconnection, which can be observed across a wide range of the electromagnetic ...
Krisztián Vida, Zsolt Kővári, Martin Leitzinger, Petra Odert, Katalin Oláh, Bálint Seli, Levente Kriskovics, Robert Greimel, Anna Mária Görgei   +8 more
doaj   +1 more source

Multiple short-term cycles in Kepler star KIC 6876668

Astronomy & Astrophysics
Context. Solar and stellar magnetic activity may have similar properties, which can be used to understand the stellar magnetic evolution. Aims. This paper examines the multiple short-term cycles in the total irradiance of the Sun and in the light curve ...
Gurgenashvili E., Zaqarashvili T. V., Reiners A., Lanza A. F., Oliver R., Albekioni M.   +5 more
doaj   +1 more source

Starspots, cycles, and magnetic fields [PDF]

Proceedings of the International Astronomical Union, 2010
AbstractI make a perhaps slightly foolhardy attempt to synthesize a semi-coherent scenario relating cycle characteristics, starspots, and the underlying magnetic fields with stellar properties such as mass and rotation. Key to this attempt is to first study single dwarfs; differential rotation plays a surprising role.
openaire   +1 more source

The magnetic fields in Be stars are stronger than previously suggested

Astronomy & Astrophysics
Context. Recent observational studies suggest that Be stars most likely are formed through the process of mass transfer in binary systems. In view of the wide consensus that the origin of the magnetic field in stars with radiative envelopes involves ...
Hubrig S., Järvinen S. P., Schöller M., Ilyin I.   +3 more
doaj   +1 more source