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Discovery of an ultra-cool subdwarf: LSR1425+7102, first star with spectral type sdM8.0

Sebastien Lepine·Michael M. Shara·R. Michael Rich
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Abstract

We report the discovery of the coolest subdwarf reported to date. The star LSR1425+7102 was discovered in our survey for faint high proper motion stars in the northern sky. Follow-up spectroscopy revealed the star to be a very red object with the characteristic signature of M subdwarfs: strong CaH bands but relatively weaker TiO bands. The CaH molecular band at $\approxλ$6900Å is particularly strong. By extrapolating the empirical relationship between the strength of the CaH molecular band and the subdwarf subtype, we conclude that LSR1425+7102 is the first star to be discovered with spectral type sdM8.0.

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Sebastien Lepine, Michael M. Shara, R. Michael Rich. 2003-01-17. Discovery of an ultra-cool subdwarf: LSR1425+7102, first star with spectral type sdM8.0. https://doi.org/10.1086/374210

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