26 citations · 83 across the 15 of their papers we have counts for
14 papers · 1 filter
Surface brightness inhomogeneity on the helium-rich hot subdwarf in the X-ray binary HD 49798
C. Simon Jeffery, Gavin Ramsay
HD 49798 is an X-ray binary consisting of a hot helium-rich subdwarf primary and an accreting compact companion with an orbital period of 1.55 d. TESS observations of its optical l…
Theoretical models for the Late Thermal Pulse in post-AGB stars: the case of DY Cen
Zhongyang Liu, C. Simon Jeffery, Xianfei Zhang +2
We present theoretical predictions of the born-again scenario for post-asymptotic giant-branch stars. An extensive model grid for born-again objects has been constructed, particula…
K2 observations of five pulsating subdwarf B stars with white dwarf companions
M. D. Reed, A. S. Baran, J. H. Telting +3
We report seismic analyses of five pulsating subdwarf B (sdBV) stars observed during Kepler's K2 mission, each with a white dwarf companion. We find three of the five to be g-mode-…
Linear and non-linear models for large-amplitude radial pulsation in faint blue stars (BLAPs)
C. S. Jeffery
The recent discovery of large-amplitude pulsations in faint blue stars (BLAPs) provides both challenges for stellar pulsation theory and opportunities to explore the late evolution…
Spectroscopic diagnostics of lead stratification in hot subdwarf atmospheres
L. J. A. Scott, C. S. Jeffery, C. M. Byrne +1
Heavy metal subdwarfs are a class of hot subdwarfs with very high abundances of heavy elements, typically around 10 000 times solar. They include stars which are strongly enhanced…
The formation of blue large-amplitude pulsators from white-dwarf main-sequence star mergers
Xianfei Zhang, C. Simon Jeffery, Jie Su +1
Blue large-amplitude pulsators (BLAPs) are hot low-mass stars which show large-amplitude light variations likely due to radial oscillations driven by iron-group opacities. Period c…
The distribution, kinematics and luminosities of extreme helium stars as probes of their origin and evolution
A. Philip Monai, P. Martin, C. S. Jeffery
Hydrogen deficient stars include the cool R CrB variable (RCBs) and hydrogen-deficient carbon (HdCs) giants through extreme helium stars (EHes) to the very hot helium-rich subdwarf…
Merged white dwarfs and nucleosynthesis
Simon Jeffery, Xianfei Zhang
Orbital decay mechanisms argue that double white dwarf mergers are inevitable, but extremely rare. Whilst some mergers result in explosions, the survivors re-ignite helium and burn…
TESS photometry of helium-rich hot subdwarfs: r modes in BD+37 442 and BD+37 1977
C. Simon Jeffery
TESS photometry of the extremely helium-rich hot subdwarfs BD+37 442 and BD+37 1977 demonstrates multi-periodic low-amplitude variability with principal periods of 0.56 and 1.14 d,…
Tidal Interactions in Post Common-Envelope sdB Binaries
Holly P. Preece, Christopher A. Tout, C. Simon Jeffery
Over half of all observed hot subdwarf B (sdB) stars are found in binaries, and over half of these are found in close configurations with orbital periods of 10 or less.…
K2 spots rotation in the helium star HD144941
C. Simon Jeffery, Gavin Ramsay
HD144941 is an evolved early-type metal-poor low-mass star with a hydrogen-poor surface. It is frequently associated with other intermediate helium-rich subdwarfs and extreme heliu…
The gravitational-wave signal generated by a galactic population of double neutron-star binaries
Shenghua Yu, C. Simon Jeffery
We investigate the gravitational wave (GW) signal generated by a population of double neutron-star binaries (DNS) with eccentric orbits caused by kicks during supernova collapse an…
The Origin and Pulsations of Extreme Helium Stars
C. Simon Jeffery
Stars consume hydrogen in their interiors but, generally speaking, their surfaces continue to contain some 70% hydrogen (by mass) throughout their lives. Nevertheless, many types o…
The hot R Coronae Borealis star DY Centauri is a binary
N. Kameswara Rao, David L. Lambert, D. A. Garcia-Hernandez +3
The remarkable hot R Coronae Borealis star DY Cen is revealed to be the first and only binary system to be found among the R Coronae Borealis (RCB) stars and their likely relatives…