Results 21 to 30 of about 5,486 (209)
FINDING EXTREME SUBDWARFS [PDF]
The Astronomical Journal, 2008 23 pages, 10 figures.
openaire +2 more sources
The Formation of Subdwarf A-type Stars [PDF]
The Astrophysical Journal, 2019 Abstract Subdwarf A-type stars (sdAs) are objects that have hydrogen-rich spectra with surface gravity similar to that of hot subdwarf stars but effective temperature below the zero-age horizontal branch. They are considered to be metal-poor main-sequence (MS) stars or extremely low-mass white dwarfs (ELM WDs).
Jinlong Yu +8 more
openaire +2 more sources
The Formation of Subdwarf B Stars [PDF]
International Astronomical Union Colloquium, 2002 AbstractWe performed full binary evolution calculations and carried out binary population synthesis studies in order to investigate the formation of subdwarf B (sdB) stars via the channels of stable Roche lobe overflow (RLOF), common envelope ejection and helium white dwarf mergers. Our model is successful in the explanation of observational properties
Han, Z +4 more
openaire +2 more sources
The Solar Neighborhood XLII. Parallax Results from the CTIOPI 0.9-m Program --- Identifying New Nearby Subdwarfs Using Tangential Velocities and Locations on the H-R Diagram [PDF]
, 2017 Parallaxes, proper motions, and optical photometry are presented for 51 systems made up 37 cool subdwarf and 14 additional high proper motion systems. Thirty-seven systems have parallaxes reported for the first time, 15 of which have proper motions of at
Henry, Todd +6 more
core +3 more sources
Purple dwarfs: New L subdwarfs from UKIDSS and SDSS
EPJ Web of Conferences, 2013 The first L subdwarf was a discovered only ten years ago. Less than ten L subdwarfs been published in the literature to date. Metal-poor ultracool atmospheres has not been well understood.
Marocco F. +7 more
doaj +1 more source
In Pursuit of the Least Luminous Galaxies
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 The dwarf galaxy companions to the Milky Way are unique cosmological laboratories. With luminosities as low as 10−7LMW, they inhabit the lowest mass dark matter halos known to host stars and are presently the most direct tracers of the distribution, mass spectrum, and clustering scale of dark matter.
Beth Willman, Regina Schulte-Ladbeck
wiley +1 more source
Radii of 88 M subdwarfs and updated radius relations for low-metallicity M-dwarf stars [PDF]
, 2018 M subdwarfs are low-metallicity M dwarfs that typically inhabit the halo population of the Galaxy. Metallicity controls the opacity of stellar atmospheres; in metal-poor stars, hydrostatic equilibrium is reached at a smaller radius, leading to smaller ...
Boeshaar, Patricia C. +11 more
core +5 more sources
A FEROS Survey of Hot Subdwarf Stars
Open Astronomy, 2018 We have completed a survey of twenty-two ultraviolet-selected hot subdwarfs using the Fiber-fed Extended Range Optical Spectrograph (FEROS) and the 2.2-m telescope at La Silla. The sample includes apparently single objects as well as hot subdwarfs paired
Vennes Stéphane +2 more
doaj +1 more source
GTC Osiris spectroscopic identification of a faint L subdwarf in the UKIRT Infrared Deep Sky Survey [PDF]
, 2009 We present the discovery of an L subdwarf in 234 square degrees common to the UK Infrared Telescope (UKIRT) Infrared Deep Sky Survey Large Area Survey Data Release 2 and the Sloan Digital Sky Survey Data Release 3.
Abazajian +34 more
core +2 more sources
Subaru and Salt Spectroscopy of Chemically Peculiar Hot Subdwarfs
Open Astronomy, 2017 The majority of hot subdwarfs lie on or close to the helium main-sequence. Many have hydrogen-rich surfaces, but a substantial fraction of the hotter subdwarfs have hydrogen-depleted or hydrogen-deficient surfaces. Amongst the former, three were known to
Jeffery C. Simon +4 more
doaj +1 more source