HS 0943+1404, a true intermediate polar

Abstract

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 Porb ~= 250 min and Pspin = 69.171 +- 0.001 min, respectively. The combination of a large ratio Pspin/Porb ~= 0.3 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 mu1 ~ 10^{34} G cm^3, 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 NII 5680, which is likely to reflect enhanced nitrogen abundances in the envelope of the secondary.

LaTeX, 10 pages, 11 figures, accepted for publication in A&A

References in corpus (12)

• Brown Dwarfs and the Cataclysmic Variable Period Minimum
• The spin periods and magnetic moments of white dwarfs in magnetic cataclysmic variables
• Cataclysmic Variables: An Empirical Angular Momentum Loss Prescription From Open Cluster Data
• HS2331+3905: The cataclysmic variable that has it all
• Anomalous ultraviolet line flux ratios in the cataclysmic variables 1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg observed with HST/STIS
• AE Aquarii: how CVs descend from supersoft binaries
• The Spin Period of EX Hydrae
• HS2237+8154: On the onset of mass transfer or entering the period gap?
• DW Cancri: a magnetic VY Scl star with an orbital period of 86 minutes
• 1RXSJ062518.2+733433: A new intermediate polar
• Time-resolved photometry and spectroscopy of the new deeply-eclipsing SW Sextantis star HS 0728+6738
• Phototmetry of V1062 Tau: low states, short outbursts, and period-switching

Cited by in corpus (14)

• Cataclysmic Variables from SDSS. VIII. The Final Year (2007-2008)
• SW Sextantis stars: the dominant population of CVs with orbital periods between 3-4 hours
• A catalogue of cataclysmic variables from 20 years of the Sloan Digital Sky Survey with new classifications, periods, trends and oddities
• VLT/FORS spectroscopy of faint cataclysmic variables discovered by the Sloan Digital Sky Survey
• Spectroscopic search for new SW Sextantis stars in the 3-4 hour orbital period range -- I
• New Cataclysmic Variables and other Exotic Binaries in the Globular Cluster 47 Tucanae
• Dwarf novae in the Hamburg Quasar Survey: Rarer than expected
• 1RXSJ173021.5-055933: a cataclysmic variable with a fast-spinning magnetic white dwarf
• HS0139+0559, HS0229+8016, HS0506+7725 and HS0642+5049: Four new long-period cataclysmic variables
• SDSS J233325.92+152222.1 and the evolution of intermediate polars
• An evolved donor star in the long-period cataclysmic variable HS 0218+3229
• An extensive photometric study of the recently discovered intermediate polar V515 And (XSS J00564+4548)
• An extensive photometric study of the recently discovered intermediate polar V647 Aur (1RXS J063631.9+353537)
• Orbital periods of cataclysmic variables identified by the SDSS. VIII. A slingshot prominence in SDSS J003941.06+005427.5?