Results 31 to 40 of about 560 (161)
A spectral differential characterization of low-mass companions
EPJ Web of Conferences, 2013 We present a new approach with which the dynamical mass of low-mass companions around cool stars can be found. In order to discover companions to late-type stars the stellar spectrum is removed.
Lyubchik Y. +4 more
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Contributions of late-type dwarf stars to the soft X-ray diffuse background
The Astrophysical Journal, 1990 Comprehensive calculations of the contribution of late-type dwarf stars to the soft X-ray diffuse background are presented. The mean X-ray luminosity as derived from optically and X-ray selected samples is examined, using the Bahcall-Soneira Galaxy model to describe the spatial distribution of stars and recent results on the X-ray spectra.
J. H. M. M. Schmitt, S. L. Snowden
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A statistical framework for the quantitative spectroscopy of luminous blue stars
Astronomy & AstrophysicsContext. Quantitative spectroscopy of luminous blue stars relies on detailed non-local thermodynamic equilibrium (non-LTE) model atmospheres whose increasing physical realism makes direct iterative analyses computationally demanding. Aims.
Urbaneja M. A.
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A Study of Abundance Patterns in the Sextans and Sculptor Dwarf Spheroidal Galaxies
The Astrophysical JournalIn this work, we employ a multicomponent decomposition model to study the Sextans and Sculptor dwarf spheroidal galaxies, which have distinct evolutionary histories.
Shuaishuai Yang +3 more
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Star formation histories of late-type dwarfs outside the Local Group
, 2001 We describe the star formation histories of three late-type dwarfs located outside the Local Group: IZw18, NGC1569 and NGC1705. The results are based on the application of the method of synthetic colour-magnitude diagrams to deep HST photometric data. All the examined galaxies were already forming stars at the reached lookback time and show no evidence
Tosi, M. +3 more
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Time-Dependent Variations of Accretion Disk [PDF]
Journal of Astronomy and Space Sciences, 1987 In dward nova we assume the primary star as a white dwarf and the secondary as the late type star which filled Roche lobe. Mass flow from the secondary star leads to the formation of thin accretion disk around the white dwarf.
Hye-Weon Na +2 more
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MONITORING OF SPECTRAL VARIATIONS OF MIRA-TYPE AND SEMIREGULAR VARIABLE STARS
Odessa Astronomical Publications, 2017 The results of monitoring of a sample of late-type variable stars (Mira Ceti-type and semiregulars) are reported. Since 1980 a sample of 60 stars has been observed in the maser line of the H2O molecule at a wavelength of 1.35 cm. These observations are
G. M. Rudnitskij
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Studies of late-type dwarfs. V - Theoretical models for lower main-sequence stars
The Astrophysical Journal, 1983 New theoretical stellar models for the lower end of the main sequence have been computed for a wide range in metallicity. These models are based on new low-temperature opacities, which include the contributions from the most important molecules, as well as published model atmospheres, which guided the choice of surface boundary conditions.
D. A. Vandenberg +3 more
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TheEUVEOptical Identification Campaign II: Late-Type and White Dwarf Stars [PDF]
International Astronomical Union Colloquium, 1996 We present optical identifications of nine previously unidentified extreme ultraviolet (EUV) sources discovered during theExtreme Ultraviolet Explorer(EUVE) satellite surveys. The all-sky survey detected four of the sources and the more sensitive deep survey detected the other five sources.
N. Craig +9 more
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First Detection of an Ultracool Dwarf at 340 MHz: VLITE Observations of EI Cancri AB
The Astronomical JournalMagnetically driven phenomena such as flaring events and aurorae lead ultracool dwarfs (UCDs) to emit at radio frequencies. Despite decades of scrutiny, a comprehensive physical understanding of their radio emission at different frequencies remains ...
Michele L. Silverstein +5 more
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