An MK-like system of spectral classification for hot subdwarfs
Drilling JS, Jeffery CS, Heber U, Moehler S, Napiwotzki R (2013)
Publication Type: Journal article
Publication year: 2013
Journal
Book Volume: 551
Article Number: A31
DOI: 10.1051/0004-6361/201219433
Abstract
An MK (Morgan-Keenan)-like system of spectral classification for hot subdwarfs is presented. We find that a three-dimensional spectral type, consisting of a "spectral" class, a "luminosity" class, and a "helium" class, is necessary to classify the sdO (subdwarf O) and sdB (subdwarf B) stars. In addition, the helium-strong stars appear to form two parallel spectral sequences: one showing strong lines of CII, CIII, or CIV, and the other with these same lines weak or absent. We also give a preliminary calibration of the new spectral types in terms of effective temperature, surface gravity, and surface helium-to-hydrogen abundance ratio, and show the relation between the new spectral types and the natural groups defined by the Palomar-Green (PG) survey. © 2013 ESO.
Authors with CRIS profile
Involved external institutions
University of Hertfordshire
United Kingdom (GB)
Louisiana State University
United States (USA) (US)
Armagh Observatory
United Kingdom (GB)
European Southern Observatory (ESO)
Germany (DE)
United Kingdom (GB)
Louisiana State University
United States (USA) (US)
Armagh Observatory
United Kingdom (GB)
European Southern Observatory (ESO)
Germany (DE)
How to cite
APA:
Drilling, J.S., Jeffery, C.S., Heber, U., Moehler, S., & Napiwotzki, R. (2013). An MK-like system of spectral classification for hot subdwarfs. Astronomy & Astrophysics, 551. https://doi.org/10.1051/0004-6361/201219433
MLA:
Drilling, J. S., et al. "An MK-like system of spectral classification for hot subdwarfs." Astronomy & Astrophysics 551 (2013).
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