spectroscopic binary

基本解释

A spectroscopic binary star, 245 light-years from Earth, one of the brightest stars in the sky and the brightest star in the constellation Virgo.
一种用分光镜观察的距地球245光年双星，是天空中最亮的恒星之一，也是处女座中最亮的星星。
odict.net
In addition, spectroscopic observations with ground-based telescopes further reveal that one of the stars is actually a tight binary that is too compact to be resolved even by Hubble.
另外，地面望远镜的分光镜观察结果进一步揭示出它们其中的一颗恒星实际上是一对紧密的双星组成的，它们距离太近以至于哈勃望远镜不能区分出来。