2005/10/27 by G. Roelofs, G. H. A. Roelofs, P. Groot +4
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Atomic physics #Cataclysmic variable star #Dwarf nova #Emission spectrum #Gamma-ray bursts and supernovae #Helium #High-pressure geophysics and materials #Mass ratio #Orbital period #Physics #Sky #Spectral line #Spectroscopy #Stars #White dwarf #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09727.x
published as Mon.Not.Roy.Astron.Soc.365:1109-1113,2006 · Accepted for publication in MNRAS
arxiv created 2005/10/27 · openalex publication_date 2005/12/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.