Results 1 to 10 of about 61,753 (216)
Metallicities and activities of southern stars [PDF]
Astronomy & Astrophysics, 2008 We present the results from high-resolution spectroscopic measurements to determine metallicities and activities of bright stars in the southern hemisphere. We have measured the iron abundances ([Fe/H]) and chromospheric emission indices (logR'HK) of 353 solar-type stars with V=7.5-9.5.
Jenkins, J. S. +5 more
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The glitch activity of neutron stars [PDF]
Astronomy & Astrophysics, 2017 We present a statistical study of the glitch population and the behaviour of the glitch activity across the known population of neutron stars. An unbiased glitch database was put together based on systematic searches of radio timing data of 898 rotation-powered pulsars obtained with the Jodrell Bank and Parkes observatories.
J. R. Fuentes +5 more
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Spectroscopy of Southern Active Stars [PDF]
International Astronomical Union Colloquium, 1991 AbstractHα and HeI D3 lines were observed in five active cool stars over their relatively short rotation periods. Three of the stars (AB Dor, Rstl37B, HD82558) are in the pre main sequence phase (as deduced from their lithium abundances), while two are post main sequence FK Comae type stars (HD32918 and BD-223467) (Vilhu et al., 1991).
O. Vilhu, B. Gustafsson, F. M. Walter
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An activity catalogue of southern stars [PDF]
Monthly Notices of the Royal Astronomical Society, 2006 We have acquired high-resolution echelle spectra of 225 F6-M5 type stars in the southern hemisphere. The stars are targets or candidates to be targets for the Anglo-Australian Planet Search. CaII HK line cores were used to derive activity indices for all of these objects. The indices were converted to the Mt.
Jenkins, J. S. +8 more
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Seismology of active stars [PDF]
Astronomische Nachrichten, 2012 AbstractIn this review we will discuss the current standing and open questions of seismology in active stars. With the longer photometric time series data that are, and will become, available from space‐missions such asKeplerwe foresee significant progress in our understanding of stellar internal structures and processes, including interactions between
Hekker, S., García, R.A.
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Living with an active star [PDF]
Astronomy & Geophysics, 2001 Observations have shown that the Sun is far from being a stable, unchanging object. Rather, we live within the outer atmosphere of a variable star. Andy Breen presents a summary of a meeting that drew together new results from observations and computational modelling of the Sun, interplanetary space and the upper atmosphere of the Earth.
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The Astrophysical Journal, 1986 Measurements of He I 5876 A and IUE measurements of chromospheric and transition region lines in a large sample of F-type stars are presented. The data show that activity is detectable in nearly all early F-type stars and differs in several of its characteristics from that typically seen in cooler stars with slow rotation and fully developed convective
Sidney C. Wolff +2 more
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, 2008 4 pages, 5 figures, to appear in the Proceedings of the ESO Workshop "Precision Spectroscopy in Astrophysics", eds. L. Pasquini, M. Romaniello, N.C.
Setiwan, J. +10 more
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ACTIVITY ON THE M STAR OF QS Vir [PDF]
The Astronomical Journal, 2010 We report analysis of VRIJH photometry, and phase-resolved optical spectroscopy of the eclipsing DA white dwarf plus dMe dwarf binary QS Vir. Modeling of the photometric data yields an inclination of $i = 74.9\pm0.6$ and a mass ratio of $q = M_2/M_1 = 0.50\pm0.05$. Our Doppler maps indicate the presence of material in the Roche lobe of the white dwarf,
Ribeiro, T. +3 more
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MAGNETO-ACTIVE LONGITUDES IN THE SUN AND STARS
Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, 2023 An overview of studies of long-term increased magnetic activity in two discrete longitudinal intervals observed on the Sun and on the surface of stars of certain types is reviewed. Active longitudes on the Sun were first discovered at the end of the 19th century.
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