Results 11 to 20 of about 146,288 (166)

Stellar Chromospheric Activity [PDF]

Living Reviews in Solar Physics, 2008
The Sun, stars similar to it, and many rather dissimilar to it, have chromospheres, regions classically viewed as lying above the brilliant photosphere and characterized by a positive temperature gradient and a marked departure from radiative equilibrium.
Hall Jeffrey C.
doaj   +3 more sources

Thermal instability and the convective stability of stellar chromospheres [PDF]

, 1970
It is generally believed that stellar chromospheres are stable against convection since the Schwarzschild criterion indicates stability when temperature increases with height. It is shown, however, that the Schwarzschild criterion does not apply to chromospheres because it ignores the possibility of thermal instability.
Defouw, Richard John
openaire   +2 more sources

Stellar Coronae And Chromospheres In The Era Of Asteroseismology

, 2018
Stellar magnetic activity is an important parameter to study as it can give insights into stellar activity cycles and even how the stellar dynamo operates. However, as cool stars evolve along the main sequence, they lose angular momentum due to magnetic braking.
Booth, R. S., Poppenhaeger, K., Watson, C. A., Silva Aguirre, V., Stello, D., Wolk, S. J.   +5 more
openaire   +3 more sources

Stellar Chromospheric Variability [PDF]

Universe, 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 coronal flares, as well as by strong Ca ii H+K and Hα emission, combined with the presence of ultraviolet ...
Richard de Grijs, Devika Kamath
openaire   +2 more sources

Evidence for Stellar Chromospheres in Globular Clusters [PDF]

Symposium - International Astronomical Union, 1987
We suggest that the conspicuous gaps frequently seen in the color-magnitude diagrams of globular clusters are caused by a sudden increase in chromospheric activity shortly after stars evolve away from the main sequence.
William Liller, Gonzalo Alcaino
openaire   +1 more source

Stellar population gradients in galaxy discs from the CALIFA survey : the influence of bars [PDF]

, 2014
We acknowledge financial support from the research projects under grants AYA2010-21887-C04-03, AYA2010-21322-C03-03 and AYA2010-15081 by the Spanish Ministerio de Ciencia e Innovación.While studies of gas-phase metallicity gradients in disc galaxies are ...
Wisotzki, L., S. Zibetti, Márquez, I., D. Mast, Papaderos, P., R. García Benito, Rosales-Ortega, F.F., Sánchez, S. F., I. Pérez, Sánchez, S.F., J. Falcón-Barroso, Ruiz Lara, T., P. Sánchez-Blázquez, R. Cid Fernandes, L. Wisotzki, G. van de Ven, de Lorenzo Cáceres, A., P. Papaderos, C. Catalán-Torrecilla, M. Mollá, González Delgado, R., Mendoza, M. A., Aguerri, J.A.L., F. F. Rosales-Ortega, Mendez Abreu, Jairo, Ruiz-Lara, T., Cid Fernandes, R., A. de Lorenzo-Caceres, J. Méndez-Abreu, Zibetti, S., T. Ruiz-Lara, Mendoza, M.A., Iglesias Paramo, Jorge, B. Husemann, Sánchez Blázquez, Patricia, Falcón Barroso, J., Bland-Hawthorn, J., M. A. Mendoza, B. Jungwiert, Catalán Torrecilla, Cristina, Mollá, M., A. Galazzi, C. J. Walcher, A. Gil de Paz, Rosales Ortega, F. F., Mast, D., Marino, Raffaella Anna, Husemann, B., De Amorim, A., J. A. L. Aguerri, Aguerri, J. A. L., Gil De Paz, Armando, Marino, R.A., J. Bland-Hawthorn, A. de Amorim, Pérez, I., R. A. Marino, Walcher, C. J., Méndez Abreu, J., I. Márquez, Walcher, C.J., Galazzi, A., Iglesias-Páramo, J., Jungwiert, B., S. F. Sánchez, R. González Delgado, De Lorenzo-Caceres Rodriguez, Adriana, Catalán-Torrecilla, C., Gil De Paz, A., Van De Ven, G., Falcón-Barroso, J., García Benito, R., Sánchez-Blázquez, P., Jorge Iglesias-Páramo   +73 more
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Fictions, Conditionals, and Stellar Astrophysics [PDF]

, 2013
This article argues in favour of an inferential role for fictions in scientific modelling. The argument proceeds by means of a detailed case study, namely models of the internal structure of stars in stellar astrophysics.
Suárez, Mauricio, Mauricio Suárez
core   +1 more source

Influence of surface stressing on stellar coronae and winds [PDF]

, 2013
STFC funding has supported this research.The large-scale field of the Sun is well represented by its lowest energy (or potential) state. Recent observations, by comparison, reveal that many solar-type stars show large-scale surface magnetic fields that ...
Morin, J., Fares, R., Jardine, Moira, Donati, J. -F., Jardine, M., Morin, Julien, Fares, Rim, Donati, J.-F., Vidotto, A. A., Donati, Jean-François, Gombosi, T. I., van Ballegooijen, A., Gombosi, Tamas I.   +12 more
core   +1 more source

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
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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
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