Results 71 to 80 of about 242,574 (198)

ROTATION PERIODS AND ACTIVITY ON RED DWARFS

Odessa Astronomical Publications, 2017
Relation between duration of cycles of photospheric activity and stellar rotation are considered here for samples of dKe-dMe stars and compared with similar ones for solar-like stars.
N. I. Bondar'
doaj   +1 more source

ON THE SEPARATION OF SOLAR AND LUNAR CYCLES

Odessa Astronomical Publications, 2014
The synodic rotation period of the Sun nearly coincides with the sidereal rotation period of the Moon (27.3 days). The 11-year cycle of solar activity coincides with the eclipse cycle Tritos.
M. S. Sidorenkov, T. S. Zhigailo
doaj   +1 more source

Detectability of Solar Rotation Period across Various Wavelengths

The Astrophysical Journal Letters
The light curves of old G dwarfs obtained in the visible and near-infrared wavelength ranges are highly irregular. This significantly complicates the detectability of the rotation periods of stars similar to the Sun in large photometric surveys, such as ...
Valeriy Vasilyev, Timo Reinhold, Alexander I. Shapiro, Theodosios Chatzistergos, Natalie Krivova, Sami K. Solanki   +5 more
doaj   +1 more source

The Nucleosynthetic Imprint of 15-40 Solar Mass Primordial Supernovae on Metal-Poor Stars

, 2010
The inclusion of rotationally-induced mixing in stellar evolution can alter the structure and composition of presupernova stars. We survey the effects of progenitor rotation on nucleosynthetic yields in Population III and II supernovae using the new ...
A. Almgren, Abel, Alexander Heger, Aoki, Bromm, Bromm, Burrows, C. C. Joggerst, Calder, Christlieb, Daniel Whalen, Frebel, Frebel, Frebel, Greif, Hamuy, Heger, Heger, J. Bell, Joggerst, Karlsson, Kitayama, Lai, Mackey, Marek, Murphy, Murphy, Nakamura, Norris, O'Shea, S. E. Woosley, Tominaga, Tominaga, Truelove, Umeda, Umeda, Whalen, Wise, Yoshida   +38 more
core   +1 more source

The Centennial Evolution of Solar Chromospheric Rotation

The Astrophysical Journal
Rotation is a prominent feature of the Sun, and it plays a crucial role in the generation and dynamic evolution of solar magnetic fields. The daily composite time series of Ca II K plage areas from 1907 February 1 to 2023 December 31 is used to analyze ...
N. B. Xiang, X. H. Zhao, L. H. Deng, F. Y. Li, M. Wan, S. Y. Qi   +5 more
doaj   +1 more source

Solar Cycle Variations of Rotation and Asphericity in the Near-Surface Shear Layer

, 2018
The precise shape of the Sun is sensitive to the influence of gravity, differential rotation, local turbulence and magnetic fields. It has been previously shown that the solar shape exhibits asphericity that evolves with the 11-year cycle.
Kosovichev, A. G., Rozelot, J. -P.
core   +3 more sources

Solar differential rotation in the period 1964 - 2016 determined by the Kanzelh\"ohe data set

, 2017
The main aim of this work is to determine the solar differential rotation by tracing sunspot groups during the period 1964-2016, using the Kanzelh\"ohe Observatory for Solar and Environmental Research (KSO) sunspot drawings and white light images.
Beljan, I. Poljančić, Brajša, R., Hanslmeier, A., Hržina, D., Jurdana-Šepić, R., Pötzi, W., Ruždjak, D., Skokić, I., Sudar, D., Veronig, A., Wöhl, H.   +10 more
core   +1 more source

Periodicities in the coronal rotation and sunspot numbers

, 2011
The present study is an attempt to investigate the long term variations in coronal rotation by analyzing the time series of the solar radio emission data at 2.8 GHz frequency for the period 1947 - 2009. Here, daily adjusted radio flux (known as Penticton
Altrock, Altrock, Badalyan, Badalyan, Bocchialini, Brajša, Brajša, Brajša, Chandra, Chandra, Cooper, Covington, Dupree, El-Raey, Fisher, Gömöry, Hansen, Hari Om Vats, Hathaway, Hathaway, Henze, Howard, Insley, Jain, Javaraiah, Kane, Karachik, Kariyappa, Kozuka, Lewis, Mehta, Mouradian, Mulec, Navarro-Peralta, Parker, Roša, Rybák, Satish Chandra, Sime, Sýkora, Tapping, Timothy, Vats, Vats, Vats, Waldemier, Weber, Weber, Zaatri   +48 more
core   +1 more source

Using Polar Faculae to Determine the Sun’s High-latitude Rotation Rate. II. Simulations and New Measurements

The Astrophysical Journal
In a previous paper, I described a new way of determining the high-latitude solar rotation rate statistically from spacetime maps of polar faculae observed in the 6767 Å continuum by the Michelson Doppler Interferometer on the Solar and Heliospheric ...
Neil R. Sheeley Jr.
doaj   +1 more source

Stellar Rotation in an Old Solar Twin Using ESPRESSO/VLT Validates Gyrochronology

The Astrophysical Journal Letters
We report the detection of rotation in the old (∼7 Gyr) solar twin HIP 73815. This result provides new insight into the validity of gyrochronology beyond the solar age, a subject of intense debate in recent years.
G. Carvalho-Silva, O. Barragán, R. D. Haywood, J. Meléndez, S. A. Barnes   +4 more
doaj   +1 more source