Results 1 to 10 of about 20,326 (120)

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
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Progress report on the monitoring active late-type stars in 2005/2006 and the analysis of V523 Cas [PDF]

Serbian Astronomical Journal, 2006
We present the light curve analysis of late-type binary V523 Cas for the season 2005. The spot has been revealed on the secondary. According to theoretical considerations, the spot appeared to be hotter than the surrounding photosphere and located at ...
Zboril M., Đurašević G.
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SULFUR ABUNDANCE IN THE GALACTIC DISC STARS

Odessa Astronomical Publications, 2013
The  sulfur abundance was determined by the synthetic spectrum method in the stars with metallicity close to that of the Sun. The comparison with the results of other authors, as well as the nucleosynthesis  computations were made.
O. P. Paramonova, T. V. Mishenina, O. Chepizhko   +2 more
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A Mini Atlas of H-Band Spectra of Southern Symbiotic Stars

Galaxies, 2023
Symbiotic stars are interacting binary systems composed of an evolved star (generally a late-type red giant) and a degenerate or dwarf companion in orbit close enough for mass transfer to occur. Understanding the status of the late-type star is important
Paula Esther Marchiano, María Laura Arias, Michaela Kraus, Michalis Kourniotis, Andrea Fabiana Torres, Lydia Sonia Cidale, Marcelo Borges Fernandes   +6 more
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ANALYSIS OF THE PARAMETERS AND ABUNDANCE OF N-CAPTURE ELEMENTS FOR FOUR STARS WITH DIFFERENT METALLICITY

Odessa Astronomical Publications, 2013
Based on the spectra obtained with echelle spectrograph SOPHIE (1.93 mtelescope, OHP,France) and the selection of lines (Basak & Mishenina, 2012). we have redefined the parameters and have determined the abundances of the elements produced in the process
N. Yu. Basak, T. V. Mishenina
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The sensitivity and behaviour of the curvature in the échelle diagram of red-giant stars

Astronomy & Astrophysics
Context. In the convective envelopes of relatively cool (surface temperature ≲6700 K) stars, oscillations are excited by turbulent convection. In these so-called solar-like oscillators, radial oscillation modes appear at nearly equally spaced frequencies.
Hekker S., Elsworth Y., Basu S., Ahlborn F., Ball W. H., Bellinger E. P., Buchele L., Espinoza-Rojas F.   +7 more
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Ensemble asteroseismology

Astronomy & Astrophysics
Context. Solar-like oscillations have to date been observed in hundreds of main-sequence and sub-giant stars. However, only a select number of detections have been made in K-type dwarfs, using extreme-precision ground-based radial velocity observations ...
Chaplin William J., Campante Tiago L., Lund Mikkel N., Nielsen Martin B., Davies Guy R., Hatt Emily, Howe Rachel, Stokholm Amalie   +7 more
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New Approach to Superflare Energy Determination

The Astrophysical Journal Letters
We present a new method for estimating the total energy radiated by stellar flares in broadband continua, which assumes a constant emitting area but incorporates a time-dependent temperature evolution.
P. Heinzel, R. Falewicz, K. Bicz, P. Preś   +3 more
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Joint Observations of PTPS Targets (JOTA)

Astronomy & Astrophysics
Context. The Pennsylvania-Toruń Planet Search, which operates on a sample of ∼1000 northern-hemisphere stars, has been underway since 2004. Stars with radial velocity (RV) amplitudes exceeding 2 km s−1 represent a backup subprogram sample dedicated to ...
Jaros R., Niedzielski A., Ali S., Srivastava D., Sierzputowska J., Adamów M., Lillo-Box J., Orikhovskyi D., Wolszczan A., Villaver E., Pribulla T., Vaňko M.   +11 more
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eROSITA’s cool star population explained

Astronomy & Astrophysics
The rotation-activity connection is the standard paradigm for interpreting chromospheric and coronal activity in late-type stars, namely, stars with outer convection zones.
Schmitt J. H. M. M., Schneider P. C., Czesla S., Freund S., Robrade J.   +4 more
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