SSSPMJ1444-2019: An extremely high proper motion, ultracool subdwarf

被引：40
作者：
Scholz, RD
Lodieu, N
McCaughrean, MJ
机构：
[1] Astrophys Inst Potsdam, D-14482 Potsdam, Germany
[2] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England
[3] Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England
来源：
ASTRONOMY & ASTROPHYSICS | 2004年 / 428卷 / 03期
关键词：
surveys; astrometry; stars : kinematics; stars; low-mass; brown dwarfs; subdwarfs; solar neighbourhood;
D O I：
10.1051/0004-6361:200400098
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
We present the discovery of a new extreme high proper motion object (similar to3.5 arcsec/year) which we classify as an ultracool subdwarf with [M/H]similar to-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)+/-(32, 77, 6) km s(-1).
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页码：L25 / L28
页数：4
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