Results 21 to 30 of about 51,001 (265)

Titanium abundances in late-type stars

Astronomy & Astrophysics, 2022
Context. The titanium abundances of late-type stars are important tracers of Galactic formation history. However, abundances inferred from Ti 
Mallinson, J. W. E., Lind, K., Amarsi, A. M., Barklem, P. S., Grumer, J., Belyaev, A. K., Youakim, K.   +6 more
core   +4 more sources

Rotation of Late-type Stars in Praesepe with K2 [PDF]

The Astrophysical Journal, 2017
Abstract We have Fourier-analyzed 941 K2 light curves (LCs) of likely members of Praesepe, measuring periods for 86% and increasing the number of rotation periods (P) by nearly a factor of four. The distribution of P versus , a mass proxy, has three different regimes:
L. M. Rebull, J. R. Stauffer, L. A. Hillenbrand, A. M. Cody, J. Bouvier, D. R. Soderblom, M. Pinsonneault, L. Hebb   +7 more
openaire   +4 more sources

A BCool magnetic snapshot survey of solar-type stars [PDF]

, 2014
SVJ acknowledges research funding by the Deutsche Forschungsgemeinschaft (DFG) under grant SFB 963/1, project A16. JM was funded by a fellowship of the Alexander von Humboldt Foundation in Göttingen.
Jeffers, S., Ramirez-Velez, J. C., Reiners, Ansgar, Carter, B.D., Donati, J. -F., Jardine, M., do Nascimento, J.-D., Collaboration, The Bcool, Petit, P., Dintrans, B.D., Ramirez-Vèlez, J., Marsden, S., do Nascimento Jr., J., Dintrans, B., Ramirez-Veles, J.C., Donati, J., Carter, Brad D., Auriere, M., Lignieres, F., Nascimento, J. D. Do, Marsden, S. C., Van Grootel, V., Morin, J., do Nascimento, J.-D., Jr., Bouvier, J., Jeffers, Sandra V., Fares, R., Theado, S., Gastine,, Gastine, Thomas, Morin, Julien, Donati, J.-F., Van Grootel, Valérie, BCool Collaboration, do Nascimento Jr., J.-D., Lanoux, J., Morgenthaler, A., Konstantinova-Antova, R., Reiners, A., Jeffers, S.V., Jeffers, S. V., Catala, C., Gastine, T., do Nascimento, J. -D., Carter, B. D., Marsden, S.C., Carter, B., Collaboration, T.   +47 more
core   +1 more source

Flare in Late-type Stars: UV [PDF]

International Astronomical Union Colloquium, 1995
Early studies of stellar flares were made entirely in the optical regime. It was recognised that flares arose from the generation of hot plasma within the stellar chromosphere at whose temperature (indicated, for instance, by the presence of a strong, blue optical continuum) a substantial emission in the ultraviolet would be expected.
openaire   +1 more source

On Technetium Abundance in Late-type Stars [PDF]

Symposium - International Astronomical Union, 1988
Technetium abundances in the atmospheres of S- and C-stars are estimated by comparing the synthetic spectra and high dispersion observed spectra for the TcI λ 5924.47 region. It was found that reliable estimates are possible only for the pure S-stars and SC-stars. For the late carbon stars only the upper limit of the Tc abundance can be found.
openaire   +1 more source

Isochrones for late-type stars [PDF]

Proceedings of the International Astronomical Union, 2008
AbstractA brief summary of the history of stellar evolution theory and the use of isochrones is given. The present state of the subject is summarized. The major uncertainties in isochrone construction are considered: chemical abundances and color calibrations, and the treatment of turbulent convection in stellar interior and atmosphere models.
openaire   +1 more source

OH Masers in Envelopes of Late Type Stars [PDF]

Symposium - International Astronomical Union, 1987
Two studies of OH maser emission in envelopes of late type stars -miras (3) and OH/IR objects- have been performed with the Nancay radio-telescope. Mainly, the OH miras are found with thicker dust envelopes than the non OH ones. A sample of unidentified IRAS point sources selected on their colors has been observed.
A.M. Le Squeren, P. Sivagnanam, F. Tran Minh, M. Dennefeld, F. Foy   +4 more
openaire   +1 more source

A magnetic snapshot survey of F-type stars [PDF]

, 2020
International audienceWe present a spectropolarimetric magnetic snapshot survey of 55 stars which includes 53 F-type stars ranging from spectral types F0 to F9 plus 2 chemically peculiar stars β CrB, and δ Cap.
Buysschaert, B., Folsom, C. P., Mengel, M. W., Neiner, C., Seach, J. M., Oksala, M. E., Marsden, S. C., Carter, B. D.   +7 more
core   +1 more source

Evolution of brightness and magnetic features of young solar-type stars – II. The young F8 star HIP 71933 [PDF]

, 2023
The early, active history of our Sun is still not fully understood. Observations of the magnetic fields on active young solar-type stars allow us an insight into the early evolution of our Sun.
Waite, I A, Perugini, G M, Burton, D M, S C Marsden, I A Waite, Hughes, J E, Marsden, S C, J E Hughes, B D Carter, D M Burton, E M Hébrard, Carter, B, Hebrard, E M, G M Perugini   +13 more
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Gravity darkening in late-type stars [PDF]

Astronomy & Astrophysics, 2018
Context.Recent interferometric data have been used to constrain the brightness distribution at the surface of nearby stars, in particular the so-called gravity darkening that makes fast rotating stars brighter at their poles than at their equator. However, good models of gravity darkening are missing for stars that posses a convective envelope.Aim.In ...
Raynaud, Raphaël, Rieutord, Michel, Petitdemange, Ludovic, Gastine, Thomas, Putigny, Bertrand   +4 more
openaire   +4 more sources