M dwarfs and the fraction of high carbon-to-oxygen stars in the solar neighbourhood. Issue 4 (1st December 2015)

• Record Type: Journal Article
• Authors: Gizis, John E.; Marks, Zachary; Hauschildt, Peter H.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 455:Issue 4(2016)
• Page Start: 3824
• Page End: 3828
• Publication Date: 2015-12-01
• Subjects: stars: abundances -- stars: carbon -- stars: low-mass; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stv2479
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We investigate the frequency of high carbon-to-oxygen (C/O = 0.9) M dwarf stars in the solar neighbourhood. Using synthetic spectra, we find that such M dwarfs would have weaker TiO bands relative to hydride features. Similar weakening has already been detected in M-subdwarf (sdM) stars. By comparing to existing spectroscopic surveys of nearby stars, we show that less than one per cent of nearby stars have high carbon-to-oxygen ratios. This limit does not include stars with C/O = 0.9, [m/H] > 0.3, and [C/Fe] > 0.1, which we predict to have low-resolution optical spectra similar to solar metallicity M dwarfs.