EDP Sciences
Free access
Issue
A&A
Volume 428, Number 3, December IV 2004
Page(s) L25 - L28
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200400098


A&A 428, L25-L28 (2004)
DOI: 10.1051/0004-6361:200400098

Letter

SSSPM J1444-2019: An extremely high proper motion, ultracool subdwarf

R.-D. Scholz1, N. Lodieu1, 2 and M. J. McCaughrean1, 3

1  Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
    e-mail: rdscholz@aip.de
2  University of Leicester, Department of Physics & Astronomy, University Road, Leicester LE1 7RH, UK
    e-mail: nl41@star.le.ac.uk
3  University of Exeter, School of Physics, Stocker Road, Exeter EX4 4QL, UK
    e-mail: mjm@aip.de, mjm@astro.ex.ac.uk

(Received 19 October 2004 / Accepted 30 October 2004)

Abstract
We present the discovery of a new extreme high proper motion object (~3.5 arcsec/year) which we classify as an ultracool subdwarf with ${\rm [M/H]} \sim -0.5$. It has a formal spectral type of sdM9 but also shows L-type features: while the VO bands are completely absent, it exhibits extremely strong TiO absorption in its optical spectrum. With a radial velocity of about -160 km s -1 and a rough distance estimate of 16-24 pc, it is likely one of the nearest halo members crossing the Solar neighbourhood with a heliocentric space velocity of $(U,V,W)=(-244,-256,-100)\pm(32,77,6)$ km s -1.


Key words: surveys -- astrometry -- stars: kinematics -- stars: low-mass, brown dwarfs -- subdwarfs -- solar neighbourhood

SIMBAD Objects



© ESO 2004