Brown dwarf star is a class of stellar objects as a mass of about 5-90 Jupiter.

棕矮星是类恒星天体的一种，质量约为5至90个木星之间。

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Nicknamed "Nemesis" or "the Death star," this undetected object could be a red or brown dwarf star, or an even darker presence several times the mass of Jupiter.

绰号“复仇者”或者“死亡之星”的未被发现的天体可能是一颗红矮星或者褐矮星，甚至是更暗的物质，质量几倍于木星。

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It took so long to find because it's an extremely dim and cool kind of failed star called a brown dwarf.

因为它亮度很低，是“不成功”的恒星——褐矮星中温度很低的一种，天文学家花了很长时间才找到它。

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The planet orbits its host star, or brown dwarf, with an orbital radius similar to that of Venus.

BBC: Tiniest extrasolar planet found