Results 81 to 90 of about 805 (173)
Ultra-cool Subdwarfs in the Subaru HSC survey
, 2018 Ultra-cool subdwarfs (UCSD) are metal-poor low-mass stars and brown dwarfs with spectral types of M, L, T, and Y. Their old ages and long lives make them effective tracers to study the history of star formation and chemical enrichment in Milky Way.
Lee, Chien-Hsiu (5595644) +7 more
core +1 more source
PRELIMINARY ABUNDANCE ANALYSIS OF 9 SUBDWARFS
Odessa Astronomical Publications, 2017 We provide parameter and abundance determination of 9 subwarfs including two SMR stars (HD 161797 and HD 182572). These stars show metallicity overabundance in agreement with previous results.
T. V. Mishenina +2 more
doaj +1 more source
New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools
, 2017 Aims. We aim to develop an efficient method to search for late-type subdwarfs (metal-depleted dwarfs with spectral types ≥M5) to improve the current statistics.
M. R. Zapatero Osorio +6 more
core +1 more source
New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools
, 2012 Aims. The aim of the project is to improve our knowledge of the low-mass and low-metallicity population to investigate the influence of metallicity on the stellar (and substellar) mass function. Methods.
M. R. Zapatero Osorio +5 more
core +1 more source
A transit survey to search for planets around hot subdwarfs
, 2021 In this presentation I give an insight of my PhD project dedicated to the search for exoplanets around hot subdwarf stars (sdO/B). I use data from the missions Kepler, K2, TESS and CHEOPS, in order to detect transits of close bodies down to the size of ...
Valérie Van Grootel +4 more
core +1 more source
Classification of Metal-Deficient Dwarfs in the Vilnius Photometric System
Open Astronomy, 2003 Methods used for the quantitative classification of metal-deficient stars in the Vilnius photometric system are reviewed. We present a new calibration of absolute magnitudes for dwarfs and subdwarfs, based on Hipparcos parallaxes.
Lazauskaitė R. +2 more
doaj +1 more source
A Universal Transition in Atmospheric Diffusion for Hot Subdwarfs Near 18,000 K [PDF]
, 2017 In the color-magnitude diagrams of globular clusters, when the locus of stars on the horizontal branch extends to hot temperatures, discontinuities are observed at colors corresponding to ∼12,000 and ∼18,000 K.
E. Dalessandro +26 more
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Hot subluminous stars: Highlights from the MUCHFUSS and Kepler missions
EPJ Web of Conferences, 2013 Research into hot subdwarf stars is progressing rapidly. We present recent important discoveries. First we review the knowledge about magnetic fields in hot subdwarfs and highlight the first detection of a highly-magnetic, helium-rich sdO star.
Geier S., Heber U., Gaensicke B.
doaj +1 more source
Microscopic diffusion and subdwarfs
, 1999 The recent distance determinations by HIPPARCOS have allowed to locate very precisely a reasonable set of subdwarfs in the HR diagram. A detailed comparison with evolutionary models is now possible and it has been recently claimed that the observed lower part of the main-sequence is cooler than the computed one.
Morel, P., Baglin, A.
openaire +2 more sources
Multicomponent stellar wind from hot subdwarfs stars
, 2010 Stellar wind from hot subdwarf stars is mainly accelerated by the interaction of ultraviolet photospheric radiation with metals, mainly oxygen. Absorbing ions share momentum through Coulombic collisions with the remaining passive part of the plasma ...
Votruba, Viktor +7 more
core +1 more source