SSSPM J1444-2019: An Extremely high proper motion, ultracool subdwarf
SSSPM J1444-2019: An Extremely high proper motion, ultracool subdwarf
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SSSPM J1444-2019：一颗极高自行、超冷亚矮星
DOI：
10.1051/0004-6361:200400098
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发表时间：
2004
影响因子：
6.5
通讯作者：
S. O. Physics
中科院分区：
文献类型：
--
作者：
R. Scholz;N. Lodieu;M. Potsdam;U. Leicester;D. PhysicsAstronomy;U. Exeter;S. O. Physics
我们发现了一个新的极高自行天体(∼3.5角秒/年)，我们将其归类为(M/H)∼−0.5的超冷亚矮星。它具有SdM9的正式光谱类型，但也显示出L类型的特征：在完全没有VO带的情况下，它在光谱中表现出极强的二氧化钛吸收。它的径向速度约为−160kM S−1，粗略估计距离为16-24pc，很可能是穿越太阳近邻最近的晕成员之一，其日心空间速度为(U，V，W)=(−2 44，−2 5 6，−10 0)±(32，77，6)km S−1。
We present the discovery of a new extreme high proper motion object (∼3.5 arcsec/year) which we classify as an ultracool subdwarf with (M/H) ∼− 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 .