Abstract
We have obtained an ultraviolet spectrum covering the range 917-1182 Å of the high-field magnetic cataclysmic variable AR Ursae Majoris when the binary was in its typical low-accretion state. The data reveal an array of deep Zeeman absorption features due to hydrogen Lyα-Lyγ, including several transitions that are normally forbidden but become enabled in the strong electric fields that exist in the atmospheres of highly magnetic white dwarfs. Spectral models indicate a magnetic field strength and structure consistent with that determined from longer wavelength Hubble Space Telescope Space Telescope Imaging Spectrograph UV observations; that is, a dipole of strength ∼235 MG offset along its axis by ∼0.15 of the stellar radius.
Original language | English |
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Pages (from-to) | 1894-1898 |
Number of pages | 5 |
Journal | Astronomical Journal |
Volume | 128 |
Issue number | 4 |
DOIs | |
Publication status | Published - Oct 2004 |