High-resolution optical spectroscopy of RS Ophiuchi during 2008 – 2009

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Somero, A., Hakala, P., Wynn, G. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP), Royal Astronomical Society 2016
• Subjects: accretion; accretion discs; techniques: spectroscopic; binaries: symbiotic; stars: individual: RS Oph; novae; cataclysmic variables; Norway; Observatorio; Leicester; Iceland
• Online Access: http://mnras.oxfordjournals.org/content/464/3/2784; http://hdl.handle.net/2381/38630; https://doi.org/10.1093/mnras/stw2551

RS Ophiuchi (RS Oph) is a symbiotic variable and a recurrent nova (RN). We have monitored it with the Nordic Optical Telescope and obtained 30 high-resolution (R = 46 000) optical spectra over one orbital cycle during quiescence. To our knowledge, this is the best-sampled high-resolution spectroscopic data set of RS Oph over one orbital period. We do not detect any direct signatures of an accretion disc such as double peaked emission lines, but many line profiles are complex consisting of superimposed emission and absorption components. We measure the spin of the red giant and conclude that it is tidally locked to the binary orbit. We observe Na I absorption features, probably arising from the circumbinary medium, that has been shaped by previous RN outbursts. We do not detect any intrinsic polarization in the optical wavelengths. AS acknowledges funding from the European Commission under the Marie Curie Host Fellowships Action for Early Stage Research Training SPARTAN programme Contract No MEST-CT- 2004-007512, University of Leicester, UK; the Finnish Graduate School in Astronomy and Space Physics; and Academy of Finland grant 277375. This work is based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. We acknowledge with thanks the variable star observations from the AAVSO International Database contributed by observers worldwide and used in this research. Peer-reviewed Publisher Version