Open AccessPhase‐resolved spectroscopy of the helium dwarf nova ‘SN 2003aw’ in quiescence
Author(s) -
Roelofs G. H. A.,
Groot P. J.,
Marsh T. R.,
Steeghs D.,
Nelemans G.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09727.x
Subject(s) - physics , astrophysics , white dwarf , dwarf nova , helium , emission spectrum , spectral line , spectroscopy , accretion (finance) , orbital period , astronomy , sky , mass ratio , cataclysmic variable star , stars , atomic physics
High time resolution spectroscopic observations of the ultracompact helium dwarf nova ‘SN 2003aw’ in its quiescent state at V ∼ 20.5 reveal its orbital period at 2027.8 ± 0.5 s or 33.80 min. Together with the photometric ‘superhump’ period of 2041.5 ± 0.5 s , this implies a mass ratio q ≈ 0.036 . We compare both the average and time‐resolved spectra of ‘SN 2003aw’ and Sloan Digital Sky Survey (SDSS) J124058.03−015919.2. Both show a DB white dwarf spectrum plus an optically thin, helium‐dominated accretion disc. ‘SN 2003aw’ distinguishes itself from the SDSS source by its strong calcium H & K emission lines, suggesting higher abundances of heavy metals than the SDSS source. The silicon and iron emission lines observed in the SDSS source are about twice as strong in ‘SN 2003aw’. The peculiar ‘double bright spot’ accretion disc feature seen in the SDSS source is also present in time‐resolved spectra of ‘SN 2003aw’, albeit much weaker.