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Mostrando ítems 11-20 de 248
On the formation of hydrogen-deficient low-mass white dwarfs
(EDP Sciences, 2020-06)
Context. Two of the possible channels for the formation of low-mass (M∗≲ 0.5 M· ) hydrogen-deficient white dwarfs are the occurrence of a very-late thermal pulse after the asymptotic giant-branch phase or a late helium-flash ...
DISCOVERY OF THE Y1 DWARF WISE J064723.23−623235.5
(The American Astronomical Society, 2013-10-20)
We present the discovery of a very cold, very low mass, nearby brown dwarf using data from the NASA Wide-field
Infrared Survey Explorer (WISE). The object,WISE J064723.23−623235.5, has a very red WISE color ofW1−W2>
3.77 ...
Lyman-alpha wing absorption in cool white dwarf stars
(Wiley, 2011-02)
Kowalski & Saumon identified the missing absorption mechanism in the observed spectra of cool white dwarf stars as the Lyman α red wing formed by the collisions between atomic and molecular hydrogen and successfully explained ...
Rotational velocities for m dwarfs
(2009)
We present spectroscopic rotation velocities (v sin i) for 56 M dwarf stars using high resolution HET HRS red spectroscopy. In addition we have also determined photometric effective temperatures, masses and metallicities ...
The Araucaria Project. Infrared Tip of the Red Giant Branch Distances to the Carina and Fornax Dwarf Spheroidal Galaxies
(2009)
We present distance determinations for two Local Group dwarf spheroidal galaxies, Carina and Fornax, based on the near-infrared magnitudes of the tip of the red giant branch (TRGB). For Carina we derive true distance moduli ...
2MASS J035523. 37+ 113343.7: A Young, Dusty, Nearby, Isolated Brown Dwarf Resembling a Giant Exoplanet
(The American Astronomical Society, 2013-01)
We present parallax and proper motion measurements, near-infrared spectra, and Wide-field Infrared Survey
Explorer photometry for the low surface gravity L5γ dwarf 2MASS J035523.37+113343.7 (2M0355). We use
these data ...
Abundance ratios of red giants in low-mass ultra-faint dwarf spheroidal galaxies
(2016)
Context. Low-mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used ...
Abundance ratios of red giants in low-mass ultra-faint dwarf spheroidal galaxies
(EDP SCIENCES, 2016-04)
Context. Low-mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used ...