Results 11 to 20 of about 5,486 (209)

Hot Subdwarf Stars [PDF]

Annual Review of Astronomy and Astrophysics, 2009
Hot subdwarf stars (sdBs, sdOs) are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. They are found in all Galactic stellar populations and are sufficiently common to account for the UV-upturn of early-type galaxies.
U. Heber
openaire   +3 more sources

New Cold Subdwarf Discoveries from Backyard Worlds and a Metallicity Classification System for T Subdwarfs

The Astrophysical Journal
We report the results of a spectroscopic survey of candidate T subdwarfs identified by the Backyard Worlds: Planet 9 program. Near-infrared spectra of 31 sources with red J  − W2 colors and large J -band reduced proper motions show varying signatures of ...
Adam J. Burgasser, Adam C. Schneider, Aaron M. Meisner, Dan Caselden, Chih-Chun Hsu, Roman Gerasimov, Christian Aganze, Emma Softich, Preethi Karpoor, Christopher A. Theissen, Hunter Brooks, Thomas P. Bickle, Jonathan Gagné, Ètienne Artigau, Michaël Marsset, Austin Rothermich, Jacqueline K. Faherty, J. Davy Kirkpatrick, Marc J. Kuchner, Nikolaj Stevnbak Andersen, Paul Beaulieu, Guillaume Colin, Jean Marc Gantier, Leopold Gramaize, Les Hamlet, Ken Hinckley, Martin Kabatnik, Frank Kiwy, David W. Martin, Diego H. Massat, William Pendrill, Arttu Sainio, Jörg Schümann, Melina Thévenot, Jim Walla, Zbigniew Wędracki, The Backyard Worlds: Planet 9 Collaboration   +36 more
doaj   +2 more sources

Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM) [PDF]

, 2007
The current classification system of M stars on the main sequence distinguishes three metallicity classes (dwarfs - dM, subdwarfs - sdM, and extreme subdwarfs - esdM).
Bessel M. S., Gizis J. E., Michael M. Shara, R. Michael Rich, Schweitzer A., Sebastien Lepine   +5 more
core   +2 more sources

Hot subdwarfs from the ESO Supernova Ia Progenitor Survey: II. Atmospheric parameters of subdwarf O stars [PDF]

, 2006
We address the origin and evolutionary status of hot subdwarf stars by studying the optical spectral properties of 58 subdwarf O (sdO) stars. Combining them with the results of our previously studied subdwarf B (sdB) stars, we aim at investigating ...
A. Stroeer, Ahmad, Baschek, Brown, Charpinet, Christlieb, D'Cruz, D. Reimers, Deetjen, Dorman, Dreizler, Driebe, Driebe, Edelmann, Ferguson, Geier, Green, Greenstein, Groth, Haas, Han, Heber, Heber, Hummer, Jeffery, Koester, Lanz, Lisker, Lisker, Maxted, Maxted, McCook, Moehler, Moehler, N. Christlieb, Napiwotzki, Napiwotzki, Napiwotzki, Ochsenbein, Paczynski, R. Napiwotzki, S. Dreizler, Schlegel, Schönberner, Schönberner, Skrutskie, Smith, Stark, Stys, Sweigart, T. Lisker, Thejll, U. Heber, Werner, Werner, Wisotzki, Østensen   +56 more
core   +4 more sources

Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary. [PDF]

Nat Astron, 2019
Rebassa-Mansergas A, Parsons SG, Dhillon VS, Ren J, Littlefair SP, Marsh TR, Torres S.   +6 more
europepmc   +3 more sources

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, T. I. Gorbaneva, L. E. Kantsen   +2 more
doaj   +2 more sources

Some Subdwarf Models

, 1962
In this paper we present the results obtained from the numerical integration of the equations for the case of subdwarfs with masses comparable and somewhat larger than that of the Sun.
Varsavsky, Carlos Manuel, Gratton, Fausto Tulio Livio, Pöppel, Wolfgang Günther León   +2 more
openaire   +2 more sources

A New Sample of Cool Subdwarfs from SDSS: Properties and Kinematics [PDF]

, 2014
We present a new sample of M subdwarfs compiled from the 7th data release of the Sloan Digital Sky Survey. With 3517 new subdwarfs, this new sample significantly increases the number of spectroscopically confirmed low-mass subdwarfs.
Andrew A. West, Antonia S. Savcheva, Bessell, Binney, Bochanski, Bochanski, Bochanski, Boeshaar, Burgasser, Costa, Covey, Dhital, Espinosa Contreras, Faherty, Fuchs, Gizis, Ivezić, Jao, Jao, Jao, John J. Bochanski, Kirkpatrick, Kirkpatrick, Kowalski, Laughlin, Luyten, Lépine, Lépine, Lépine, Lépine, Lépine, Mann, Monteiro, Morgan, Munn, Munn, Murray, Reid, Reid, Schlegel, Schmidt, Skrutskie, Subasavage, Subasavage, West, West, West, West, York   +48 more
core   +3 more sources

Kinematics of nearby subdwarf stars [PDF]

Astronomy & Astrophysics, 2005
We present an analysis of the space motions of 742 subdwarf stars based on the sample of Carney et al. (1994, CLLA). Hipparcos parallaxes, TYC2+HIP proper motions and Tycho2 proper motions were combined with radial velocities and metallicities from CLLA. The kinematical behavior is discussed in particular in relation to their metallicities.
Arifyanto, M. I., Fuchs, B., Jahreiss, H., Wielen, R.   +3 more
openaire   +2 more sources

Multiplicity of the Galactic Senior Citizens: A high-resolution search for cool subdwarf companions [PDF]

, 2014
Cool subdwarfs are the oldest members of the low mass stellar population. Mostly present in the galactic halo, subdwarfs are characterized by their low metallicity.
Baranec, Christoph, Fuchs, Joshua T., Law, Nicholas M., Riddle, Reed L., Ziegler, Carl   +4 more
core   +4 more sources