Noun
spectroscopic binary (plural spectroscopic binaries)
(astronomy) A binary star in which the component stars are close together and can only be resolved via spectroscopy
Delta is a spectroscopic binary system composed of two yellow main sequence stars of similar dimensions to the Sun that lies 35 light-years from Earth. Source: Internet
It is a spectroscopic binary, with a companion 0.36 AU distant, and a third star—an orange main-sequence star of spectral type K0—8100 AU distant. Source: Internet
Rigel B is itself a spectroscopic binary system, consisting of two main sequence stars that orbit each other every 9.86 days. Source: Internet
K 1-2 is a planetary nebula whose central star is a spectroscopic binary composed of two stars in close orbit with jets emanating from the system. Source: Internet
Such a system is known as a double-lined spectroscopic binary (often denoted "SB2"). Source: Internet