Search for nearby stars among proper motion stars selected by opticaltoinfrared photometr.pdf
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Astronomy Astrophysics manuscript no.
(will be inserted by hand later)
Search for nearby stars among proper motion stars selected by
optical-to-infrared photometry
I. Discovery of LHS 2090 at spectroscopic distance of d ∼ 6 pc
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0 1 2,⋆ 3
R.-D. Scholz , H. Meusinger , and H. Jahreiß
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1 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D–14482 Potsdam, Germany
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u 2 e-mail: rdscholz@aip.de
J Th¨uringer Landessternwarte Tautenburg, D–07778 Tautenburg, Germany
e-mail: meus@obelix.tls-tautenburg.de
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1 Astronomisches Rechen-Institut, M¨onchhofstraße 12-14, D–69120 Heidelberg, Germany
e-mail: hartmut@ari.uni-heidelberg.de
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v Received ; accepted
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2 Abstract. We present the discovery of a previously unknown very nearby star - LHS 2090 at a distance of
2 only d = 6 pc. In order to find nearby (i.e. d 25 pc) red dwarfs, we re-identified high proper motion stars
6 (µ 0.18 arcsec/yr) from the NLTT catalogue (Luyten 1979-1980) in optical Digitized Sky Survey data for
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1 two different epochs and in the 2MASS data base. Only proper motion stars with large R − Ks colour index
0 and with relatively bright infrared magnitudes (Ks 10) were selected for follow-up spectroscopy. The low-
/ resolution spectrum of LHS 2090 and its large proper motion (0.79 arcsec/yr) classify this star as an M6.5 dwarf.
h The resulting spectroscopic distance estimate from comparing the infrared JHKs magnitudes of LHS 2090 with
p absolute magnitudes of M6.
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