Hubble Space Telescope Parallaxes of AM CVn Stars and Astrophysical Consequences
- G. Roelofs, P. Groot, G. Nelemans
- Physics
- 25 May 2007
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
- P. Maxted, D. O'donoghue, Hertfordshire
- Physics, Geology
- 31 January 2007
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
- T. Ash, A. Reynolds, P. Roche, A. Norton, M. Still, L. Morales-Rueda
- Physics, Geology
- 1 August 1999
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…
Photometry of four binary subdwarf B stars and the nature of their unseen companion stars
- P. Maxted, T. Marsh, Australia.
- Physics, Geology
- 8 February 2002
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…
DISCOVERY OF A CLOSE SUBSTELLAR COMPANION TO THE HOT SUBDWARF STAR HD 149382—THE DECISIVE INFLUENCE OF SUBSTELLAR OBJECTS ON LATE STELLAR EVOLUTION
- S. Geier, H. Edelmann, U. Heber, L. Morales-Rueda
- Physics, Geology
- 7 August 2009
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…
The stellar mass ratio of GK Persei
- L. Morales-Rueda, M. Still, San Diego State University
- Physics
- 15 October 2001
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…
Cataclysmic variables from a ROSAT/2MASS selection — I. Four new intermediate polars
- B. Gaensicke, T. Marsh, A. Aungwerojwit
- Physics
- 21 April 2005
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…
Six detached white-dwarf close binaries
- L. Morales-Rueda, T. Marsh, U. Leicester
- Physics, Geology
- 21 February 2005
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,…
Orbital periods of 22 subdwarf B stars
- L. Morales-Rueda, P. Maxted, Universitat Erlangen-Nurnberg
- Physics
- 23 September 2002
Subdwarf B (sdB) stars are thought to be core helium burning stars with low mass hydrogen envelopes. In recent years it has become clear that many sdB stars lose their hydrogen through interaction…
Hot subdwarf stars in close-up view - II. Rotational properties of single and wide binary subdwarf B stars
- S. Geier, U. Heber, H. Edelmann, R. Napiwotzki, L. Morales-Rueda
- Physics
- 13 December 2011
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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