Volume 440, Number 2, September III 2005
|Page(s)||701 - 709|
|Section||Stellar structure and evolution|
|Published online||01 September 2005|
HS 0943+1404, a true intermediate polar
Department of Physics, University of Warwick, Coventry CV4 7AL, UK e-mail: firstname.lastname@example.org
2 Instituto de Astrofísica de Canarias, Vía Láctea, s/n, La Laguna, 38205 Santa Cruz de Tenerife, Spain
3 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
4 Hida Observatory, Kyoto University, Kamitakara, Gifu 506-1314, Japan
5 Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
6 Tuorla Observatory, Turku University, Väisäläntie 20, 21500 Piikkiö, Finland
7 Department of Physics, 20014 University of Turku, Finland
8 School of Physics, University of Exeter, Exeter EX4 4QL, UK
9 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
Accepted: 1 June 2005
We have identified a new intermediate polar, HS 0943+1404, as part of our ongoing search for cataclysmic variables in the Hamburg Quasar Survey. The orbital and white dwarf spin periods determined from time-resolved photometry and spectroscopy are min and min, respectively. The combination of a large ratio and a long orbital period is very unusual compared to the other known intermediate polars. The magnetic moment of the white dwarf is estimated to be , which is in the typical range of polars. Our extensive photometry shows that HS 0943+1404 enters into deep (~3 mag) low states, which are also a characteristic feature of polars. We therefore suggest that the system is a true “intermediate” polar that will eventually synchronise, that is, a transitional object between intermediate polars and polars. The optical spectrum of HS 0943+1404 also exhibits a number of unusual emission lines, most noticeably Nλ5680, which is likely to reflect enhanced nitrogen abundances in the envelope of the secondary.
Key words: accretion, accretion disc / stars: binaries: close / stars: novae, cataclysmic variables
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.