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Hubble Space Telescope Parallaxes of AM CVn Stars and Astrophysical Consequences
We present absolute parallaxes and relative proper motions for five AM CVn stars, which we obtained using the Fine Guidance Sensors on board the Hubble Space Telescope. Our parallax measurements
The mass and radius of the M-dwarf in the short-period eclipsing binary RR Caeli
We present new photometry and spectroscopy of the eclipsing white dwarf‐M-dwarf binary star RR Cae. We use timings of the primary eclipse from white-light photo-electric photometry to derive a new
The mass of the neutron star in Centaurus X-3
We report new radial velocity observations of V779 Cen, the optical companion to the X-ray pulsar Cen X-3. Two sets of results at two epochs yield very different radial velocity amplitudes. We
The stellar mass ratio of GK Persei
We study the absorption lines present in the spectra of the long-period cataclysmic variable GK Per during its quiescent state, which are associated with the secondary star. By comparing quiescent
DISCOVERY OF A CLOSE SUBSTELLAR COMPANION TO THE HOT SUBDWARF STAR HD 149382—THE DECISIVE INFLUENCE OF SUBSTELLAR OBJECTS ON LATE STELLAR EVOLUTION
Substellar objects, like planets and brown dwarfs orbiting stars, are by-products of the star formation process. The evolution of their host stars may have an enormous impact on these small
Cataclysmic variables from a ROSAT/2MASS selection — I. Four new intermediate polars
We report the first results from a new search for cataclysmic variables (CVs) using a combined X-ray (ROSAT)/infrared (2MASS) target selection that discriminates against background active galactic
Photometry of four binary subdwarf B stars and the nature of their unseen companion stars
We present light curves of four binary subdwarf B stars (sdB), Ton 245, Feige 11, PG 1432+159 and PG 1017−086. We also present new spectroscopic data for PG 1017−086 from which we derive its orbital
Six detached white-dwarf close binaries
We determine the orbits of four double-degenerate systems (DDs), composed of two white dwarfs and two white-dwarf-M-dwarf binaries. The four DDs, WD1022+050, WD1428+373, WD1824+040 and WD2032+188,
Initial data release from the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS)
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in Hα, rand ifilters, with the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton
Hot subdwarf stars in close-up view - II. Rotational properties of single and wide binary subdwarf B stars
Subluminous B stars (sdBs) form the extremely hot end of the horizontal branch and are therefore related to the blue horizontal branch (BHB) stars. While the rotational properties of BHB stars have
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