Results 71 to 80 of about 151,165 (141)

Constraining planet structure from stellar chemistry : the cases of CoRoT-7, Kepler-10, and Kepler-93 [PDF]

, 2015
This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012,
Mortier, Annelies, A. Mortier, Dorn, Caroline, Sousa, S. G., Santos, N. C., Delgado-Mena, E., Benz, Willy, Mordasini, Christoph, Pepe, F., Mortier, A.; id_orcid, Mortier, A., F. Pepe, Figueira, P., Adibekyan, V., Udry, S., C. Mordasini, A. Santerne, Santerne, A., W. Benz, Dorn, C., V. Adibekyan, E. Delgado-Mena, Buchhave, L., S. G. Sousa, Mordasini, C., S. Udry, N. C. Santos, Buchhave, Lars A., Benz, W., P. Figueira, L. Buchhave, C. Dorn   +31 more
core   +3 more sources

Stellar Chromospheric Activity Database of Solar-like Stars Based on the LAMOST Low-resolution Spectroscopic Survey. III. Calibrating the Chromospheric Basal Flux and the Connection to Stellar Rotation

The Astrophysical Journal Supplement Series
Based on the Ca ii H and K lines observed by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, we employ the photospheric ( ${R}_{{\rm{HK}}}^{{\prime} }$ ) and basal ( ${R}_{{\rm{HK}},L}^{+}$ ) flux-calibrated chromospheric activity indices ...
Weitao Zhang, Han He, Jun Zhang
doaj   +1 more source

Investigating the Temperature Sensitivity of UV Line Ratios in the 280 nm Region of Solar-like Stars

The Astrophysical Journal
Stellar UV spectra are fundamental diagnostics of physical and magnetic properties of stars. For instance, lines like Mg ii at 280 nm serve as valuable indicators of stellar activity, providing insights into the activity levels of Sun-like stars and ...
Valentina Penza, Serena Criscuoli, Raffaele Reda, Luca Bertello, Giuseppe Bono, Dario Del Moro, Valentina D’Orazi, Luca Giovannelli, Giuseppina Nigro, Francesco Berrilli   +9 more
doaj   +1 more source

Stellar Parameters and Magnetic Activity of Eruptive Variable Stars Based on TESS Light Curves and the LAMOST Spectral Survey

The Astrophysical Journal Supplement Series
Eruptive variable stars are an important type of variable stars. We investigate the chromospheric activity and white-light flare properties of International Variable Star Index (VSX)-selected eruptive stars by combining LAMOST DR10 low-resolution ...
Yanan Wang, Li-yun Zhang, Tianhao Su, Xianming L. Han, Prabhakar Misra   +4 more
doaj   +1 more source

Theoretical studies of chromospheres and winds in cool stars [PDF]

, 1984
The atmospheres of hot pre-main sequence stars are discussed along with FU Orionis winds, h alpha emission from M dwarfs, and envelopes of T Tauri stars.
Hartmann, L.
core  

The Strength and Variability of the Helium 10830 Å Triplet in Young Stars, with Implications for Exosphere Detection

The Astronomical Journal
Young exoplanets trace planetary evolution, in particular the atmospheric mass loss that is most dynamic in youth. However, the high activity level of young stars can mask or mimic the spectroscopic signals of atmospheric mass loss.
Daniel M. Krolikowski, Adam L. Kraus, Benjamin M. Tofflemire, Caroline V. Morley, Andrew W. Mann, Andrew Vanderburg   +5 more
doaj   +1 more source

X-shooter spectroscopy of young stellar objects

, 2013
Context. Traditionally, the chromospheres of late-type stars are studied through their strongest emission lines, Hα and Ca ...
E. Covino, A. Natta, V. D???Elia, G. Cupani, S. Randich, V. D’Elia, A. Frasca, J. M. Alcal??, K. Biazzo, E. Rigliaco, S. Covino, F. Comerón, B. Stelzer, L. Spezzi, L. Testi, C. F. Manara, J. M. Alcalá   +16 more
core   +1 more source

The Influence of Chromospheric Activity on Line Formation

The Astrophysical Journal
One of the primary sources of stellar spectral variability is magnetic activity. While our current understanding of chromospheric activity is largely derived from specific lines sensitive to chromospheric heating, such as the Ca ii H and K doublet ...
Mariela C. Vieytes, Lily L. Zhao, Megan Bedell   +2 more
doaj   +1 more source

Betelgeuse: Detection of the Expanding Wake of the Companion Star

The Astrophysical Journal
Recent analyses conclude that Betelgeuse, a red supergiant star (HD 39801), likely has a companion object with a period of ∼2000 days orbiting at only 2.3 R _⋆ , deep in the chromosphere of the supergiant.
Andrea K. Dupree, Paul I. Cristofari, Morgan MacLeod, Kateryna Kravchenko   +3 more
doaj   +1 more source

Definition and empirical structure of the range of stellar chromospheres-coronae across the H-R diagram: Cool stars [PDF]

, 1986
Major advances in our understanding of non-radiative heating and other activity in stars cooler than T sub eff = 10,000K has occured in the last few years.
Linsky, J. L.
core