Results 101 to 110 of about 7,790 (232)

Meet the family − the catalog of known hot subdwarf stars

Open Astronomy, 2017
In preparation for the upcoming all-sky data releases of the Gaia mission, we compiled a catalog of known hot subdwarf stars and candidates drawn from the literature and yet unpublished databases.
Geier Stephan, Østensen Roy H., Nemeth Peter, Heber Ulrich, Gentile Fusillo Nicola P., Gänsicke Boris T., Telting John H., Green Elizabeth M., Schaffenroth Johannes   +8 more
doaj   +2 more sources

Hydrogen in hot subdwarfs formed by double helium white dwarf mergers [PDF]

, 2016
Isolated hot subdwarfs might be formed by the merging of two helium-core white dwarfs. Before merging, helium-core white dwarfs have hydrogen-rich envelopes and some of this hydrogen may survive the merger.
Philip D. Hall, C. Jeffery
semanticscholar   +1 more source

The Arizona-Montréal Spectroscopic Survey of hot subluminous stars★

Astronomy & Astrophysics
Context. Hot subdwarf B (sdB) and O (sdO) type stars are evolved helium-burning objects that lost their hydrogen envelope before the helium flash when their progenitors were close to the tip of the red giant branch (RGB).
Latour M., Green E. M., Dorsch M., Van Grootel V., Chayer P., Charpinet S., Heber U., Randall S. K., Ma X.-Y.   +8 more
doaj   +1 more source

An Examination of Recent Transformations to the BV(RI)_C Photometric System from the Perspective of Stellar Models for Old Stars

, 2010
Isochrones for ages > 4 Gyr and metallicities in the range -2.5 < [Fe/H] < +0.3 that take the diffusion of helium and recent advances in stellar physics into account are compared with observations in the Johnson-Cousins BV(RI)_C photometric system for ...
Bahcall, Bergbusch, Bergbusch, Bessell, Bessell, Boesgaard, Bohlin, Brasseur, Cacciari, Calamida, Caldwell, Carretta, Casagrande, Cassisi, Cayrel de Strobel, Christensen-Dalsgaard, Clem, Don A. VandenBerg, Dotter, Dotter, Edvardsson, Gratton, Kaluzny, Koch, Kučinskas, L. Casagrande, Magic, McCall, Meléndez, Meléndez, Michaud, Milone, Paulson, Peter B. Stetson, Pietrinferni, Ramírez, Reid, Rood, Sarajedini, Schlegel, Skrutskie, Stetson, Tautvaišiene, VandenBerg, VandenBerg, VandenBerg, VandenBerg, VandenBerg, VandenBerg, Weiss, Weiss, Yong   +51 more
core   +1 more source

MUCHFUSS - Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS [PDF]

, 2012
The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars with massive compact companions (white dwarfs with masses $M>1.0 {\rm M_{\odot}}$, neutron stars or black holes). The existence
Abazajian, Coenen, For, Geier, Geier, Geier, Geier, Geier, Geier, Han, Han, Heber, Lisker, Maxted, Maxted, Mereghetti, Napiwotzki, Nelemans, Nelemans, Pfahl, Podsiadlowski, Pollacco, Schuh, Soker, Tillich, Yungelson, Østensen   +26 more
core   +2 more sources

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

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.
T. Brown, Joanna M. Taylor, S. Cassisi, A. Sweigart, A. Bellini, L. Bedin, M. Salaris, A. Renzini, E. Dalessandro   +8 more
semanticscholar   +1 more source

The Classificiation of Kepler B star Variables

, 2012
The light curves of 252 B-star candidates in the Kepler data base are analyzed in a similar fashion to that done by Balona et al. (2011) to further characterize B star variability, increase the sample of variable B stars for future study, and to identify
Jackiewicz, Jason, McKeever, Jean, McNamara, Bernard J.   +2 more
core   +1 more source

The Formation of Blue Large-amplitude Pulsators from White-dwarf Main-sequence Star Mergers

The Astrophysical Journal, 2023
Blue large-amplitude pulsators (BLAPs) are hot low-mass stars that show large-amplitude light variations likely due to radial oscillations driven by iron group opacities. Period changes provide evidence of both secular contraction and expansion among the
Xianfei Zhang, C. Simon Jeffery, Jie Su, Shaolan Bi   +3 more
doaj   +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., Bartkevičius A., Bartašiūtė S.   +2 more
doaj   +1 more source