Results 11 to 20 of about 14,785 (302)

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   +1 more source

Stellar Chromospheric Variability

, 2021
Cool stars with convective envelopes of spectral types F and later tend to exhibit magnetic activity throughout their atmospheres. The presence of strong and variable magnetic fields is evidenced by photospheric starspots, chromospheric plages and ...
Richard de Grijs, Devika Kamath
core   +1 more source

Disentangling planetary orbits from stellar activity in radial-velocity surveys [PDF]

, 2013
The majority of extra-solar planets have been discovered (or confirmed after follow-up) through radial-velocity (RV) surveys. Using ground-based spectrographs such as High Accuracy Radial Velocity Planetary Search (HARPS) and HARPS-North, it is now ...
Segransan, Damien, Pollacco, Don, Fares, R, Pollacco, D, Queloz, D., Haywood, R.D., Pollacco, D., Gillon, M, Gillon, M., Barros, SCC, Lanza, AF, Pepe, F., Cameron, A. Collier, Hatzes, A., Ségransan, D., Lovis, C, Lovis, Christophe, Moutou, C, Barros, S. C. C., Santerne, A., Unruh, Y., Haywood, R. D., Unruh, Y, Fares, R., Segransan, D, Moutou, C., Deleuil, M., Barros, S.C.C., Cameron, AC, Lanza, A.F., Pepe, F, Deleuil, M, Haywood, RD, Gillon, Michaël, Pepe, Francesco Alfonso, Santerne, A, Queloz, Didier, Lovis, C., Cameron, A.C., Hatzes, A, Lanza, A. F., Queloz, D   +41 more
core   +1 more source

Theoretical Predictions of Surface Light Element Abundances in Protostellar and Pre-Main Sequence Phase

Frontiers in Astronomy and Space Sciences, 2021
Theoretical prediction of surface stellar abundances of light elements–lithium, beryllium, and boron–represents one of the most interesting open problems in astrophysics.
E. Tognelli, E. Tognelli, S. Degl’Innocenti, S. Degl’Innocenti, P. G. Prada Moroni, P. G. Prada Moroni, L. Lamia, L. Lamia, L. Lamia, R. G. Pizzone, A. Tumino, A. Tumino, C. Spitaleri, C. Spitaleri, A. Chiavassa   +14 more
doaj   +1 more source

Investigation of ρ Cas (HR 9045, HD 224014) stellar atmosphere [PDF]

Serbian Astronomical Journal
The atmosphere of hypergiant ρ Cas is investigated by the method of atmospheric model. Effective temperature and the surface of gravity are determined by comparing the observed and theoretical values of photometrical indices [c1];Q, and ...
Samedov Z.A., Hajieva G.M.
doaj   +1 more source

Turbulence-supported Massive Star Envelopes

The Astrophysical Journal Letters, 2023
The outer envelopes of massive ( M ≳ 10 M _⊙ ) stars exhibit large increases in opacities from forests of lines and ionization transitions (particularly from iron and helium) that trigger near-surface convection zones. One-dimensional (1D) models predict
William C. Schultz, Lars Bildsten, Yan-Fei Jiang   +2 more
doaj   +1 more source

Stellar Flare Statistics - Physical Consequences [PDF]

International Astronomical Union Colloquium, 1989
AbstractThe observational data permit us to establish clear statistical correlations between different parameters of stellar flare activity and the characteristics of quiet stars. These relations are: (i)between energies and frequencies of flares on stars of different luminosities;(ii)between total radiation energies of flares and quiet stars both in X-
openaire   +1 more source

Inversions of Stellar Structure From Asteroseismic Data

Frontiers in Astronomy and Space Sciences, 2022
The advent of space-based photometry missions in the early 21st century enabled the application to asteroseismic data of advanced inference techniques until then restricted to the field of helioseismology.
Gaël Buldgen, Jérôme Bétrisey, Ian W. Roxburgh, Ian W. Roxburgh, Sergei V. Vorontsov, Sergei V. Vorontsov, Daniel R. Reese   +6 more
doaj   +1 more source

From theoretical stellar spectra to realistic models of the Milky Way : a never ending Odyssey [PDF]

, 2007
The last chapter is dedicated to the compilation of the results and the discussion about the success of - but also about the problems that have arisen during - and in part also survived - this work. The main goal of this thesis was, firstly, to convert
Ammon, Karin
core   +1 more source

Solar and stellar rotation [PDF]

, 2007
Workshop on Solar and Stellar Physics through Eclipses -- MAR 27-29, 2006 -- Ankara Univ, ORSEM Campus, Side, Antalya, TURKEYThe secular evolution of the stellar rotation through angular momentum loss, driven by the stellar wind, and the consequences of ...
Demircan, O., Filiz-Ak, N., Eker, Z.
core   +1 more source