Epsilon Indi B: a new benchmark T dwarf
Epsilon Indi B: a new benchmark T dwarf
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Epsilon Indi B：新基准 T 矮星
DOI：
10.1051/0004-6361:20021847
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
H. Sternwarte
中科院分区：
文献类型：
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作者：
R. Scholz;M. McCaughrean;N. Lodieu;B. H. A. I. Potsdam;H. Sternwarte
我们已经发现了一颗新的早期T矮星，它距离太阳只有3.6pc，是K5 V星星Eppery Indi（HD 209100）的共同自行伴星（距离1459 AU）。正因如此，印度矮行星B是太阳系外最高的自行源之一（约4.7角秒/年），是距离太阳最近的20个恒星系统之一的一部分，也是距离太阳最近的棕矮星。从SuperCOSMOS巡天获得的光学测光与2 MASS Quicklook巡天数据发布的近似红外测光相结合，产生早期T矮星典型来源的颜色。使用ESO NTT和SOFI进行的后续红外光谱确认其光谱类型为T2.5+/-0.5。KS=11.2，Epperium Indi B比任何已知的T矮星亮1.7等，比同类中的典型天体亮4等，使其非常适合详细研究。此外，作为附近一颗明亮星星的伴星，它有一个精确的已知距离（3.626 pc）和相对已知的年龄（0.8- 2 Gyr），使我们能够估计它的光度为logL/Lsun=-4.67，有效温度为1260 K，质量为~40- 60 Mjup。Ependium Indi B是太阳附近普查的一个重要补充，同样重要的是，它是我们了解亚恒星物体的一个新基准物体。
We have identified a new early T dwarf only 3.6pc from the Sun, as a common proper motion companion (separation 1459AU) to the K5V star Epsilon Indi (HD209100). As such, Epsilon Indi B is one of the highest proper motion sources outside the solar system (~4.7 arcsec/yr), part of one of the twenty nearest stellar systems, and the nearest brown dwarf to the Sun. Optical photometry obtained from the SuperCOSMOS Sky Survey was combined with approximate infrared photometry from the 2MASS Quicklook survey data release, yielding colours for the source typical of early T dwarfs. Follow up infrared spectroscopy using the ESO NTT and SOFI confirmed its spectral type to be T2.5+/-0.5. With Ks=11.2, Epsilon Indi B is 1.7 magnitudes brighter than any previously known T dwarf and 4 magnitudes brighter than the typical object in its class, making it highly amenable to detailed study. Also, as a companion to a bright nearby star, it has a precisely known distance (3.626pc) and relatively well-known age (0.8-2Gyr), allowing us to estimate its luminosity as logL/Lsun=-4.67, its effective temperature as 1260K, and its mass as ~40-60Mjup. Epsilon Indi B represents an important addition to the census of the Solar neighbourhood and, equally importantly, a new benchmark object in our understanding of substellar objects.