Results 31 to 40 of about 117,260 (302)
Wear of Functionally Graded Coatings under Frictional Heating Conditions
Nanomaterials, 2021 Multilayered and functionally graded coatings are extensively used for protection against wear of the working surfaces of mechanisms and machines subjected to sliding contact.
Vladimir B. Zelentsov +2 more
doaj +1 more source
HST Spectra of GW Librae: A Hot Pulsating White Dwarf in a Cataclysmic Variable [PDF]
, 2002 We have obtained Hubble Space Telescope UV spectra of the white dwarf in GW Lib, the only known non-radially pulsating white dwarf in a cataclysmic variable, and the first known DAZQ variable. The UV light curve reveals large amplitude (10%) pulsationsin
Boris T. Gänsicke +4 more
core +3 more sources
Confining the Edges of the GW Vir Instability Strip [PDF]
International Astronomical Union Colloquium, 1995 AbstractGround based optical spectroscopy as well as EUVE and HST observations are used for model atmosphere analyses of PG1159 stars in order to confine the GW Vir instability strip.
Werner, Klaus +3 more
openaire +4 more sources
DISCOVERY OF TWO LITHIUM CEPHEIDS IN THE GALAXY
Odessa Astronomical Publications, 2017 We report about the discovery of two lithium Cepheids in the Galaxy, based on observations made with the echelle spectrograph of the Apache Point Observatory. We have used high- resolution, high signal-to-noise spectra to determine abundances of chemical
V. V. Kovtyukh +2 more
doaj +1 more source
Symmetry-breaking instability in a prototypical driven granular gas [PDF]
, 2002 Symmetry-breaking instability of a laterally uniform granular cluster (strip state) in a prototypical driven granular gas is investigated. The system consists of smooth hard disks in a two-dimensional box, colliding inelastically with each other and ...
A. Kudrolli +25 more
core +1 more source
Towards a pure ZZ Ceti instability strip [PDF]
Astronomy & Astrophysics, 2006 12 pages, 3 ...
Castanheira, B. G. +10 more
openaire +2 more sources
Pulsation in Intermediate-Mass Stars
Frontiers in Astronomy and Space Sciences, 2018 A new perspective of pulsation in stars within the δ Scuti instability strip has recently emerged as a result of Kepler observations. The majority of stars within the instability strip do not pulsate and practically all δ Scuti stars contain low ...
Luis A. Balona
doaj +1 more source
TESS Observations of the Pleiades Cluster: A Nursery for δ Scuti Stars
The Astrophysical Journal Letters, 2023 We studied 89 A- and F-type members of the Pleiades open cluster, including five escaped members. We measured projected rotational velocities ( $v\sin i$ ) for 49 stars and confirmed that stellar rotation causes a broadening of the main sequence in the ...
Timothy R. Bedding +10 more
doaj +1 more source
On the possible existence of short-period g-mode instabilities powered by nuclear burning shells in post-AGB H-deficient (PG1159-type) stars [PDF]
, 2009 We present a pulsational stability analysis of hot post-AGB H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete ...
A. H. Córsico +13 more
core +5 more sources
Moving Through The Instability Strip [PDF]
International Astronomical Union Colloquium, 1993 The purpose: To look at period changes in pulsating variables from the point of view of stellar evolution. Is there evidence of systematic, slow changes that might be caused by the changes in mean density during passage across the Instability Strip?The data: O – C diagrams for 67 RR Lyrae stars and Cepheids by student assistants at the Maria Mitchell ...
openaire +1 more source