| Issue |
A&A
Volume 390, Number 3, August II 2002
|
|
|---|---|---|
| Page(s) | L27 - L30 | |
| Section | Letters | |
| DOI | https://doi.org/10.1051/0004-6361:20020928 | |
| Published online | 14 August 2002 | |
Letter to the Editor
Search for nearby stars among proper motion stars selected by optical-to-infrared photometry*
II. Two late M dwarfs within 10 pc
Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany e-mail: rdscholz@aip.de; nlodieu@aip.de
Corresponding author: M. J. McCaughrean, mjm@aip.de
Received:
7
May
2002
Accepted:
17
June
2002
We have identified two late M dwarfs within 10 pc of the Sun, by
cross-correlating the Luyten NLTT catalogue of stars with proper motions
larger than 0.18 arcsec/yr, with objects lacking optical identification in the
2MASS data base. The 2MASS photometry was then combined with improved optical
photometry obtained from the SuperCOSMOS Sky Surveys. The two objects
(LP 775- 31 and LP 655- 48) have extremely red optical-to-infrared colours
() ~ ) and very bright infrared magnitudes
( < ): follow-up optical spectroscopy with the
ESO 3.6-m telescope gave spectral types of M 8.0 and M 7.5 dwarfs,
respectively. Comparison of their near-infrared magnitudes with the absolute
magnitudes of known M 8 and M 7.5 dwarfs with measured trigonometric
parallaxes yields spectroscopic distance estimates of 
pc and
pc for LP 775- 31 and LP 655- 48, respectively. In contrast,
Cruz & Reid ([CITE]) recently determined spectral types of M 6 for both objects,
and commensurately larger distances of 
pc and 
pc.
LP 655- 48 is also a bright X-ray source (1RXS J044022.8-053020).
With only a few late M dwarfs previously known within 10 pc, these two
objects represent an important addition to the census of the Solar
neighbourhood.
Key words: astrometry and celestial mechanics: astrometry / astronomical data base: surveys / stars: late-type / stars: low mass, brown dwarfs
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.