Astrophysics (Index)About

spectroscopic binary

(binary star detected by movement indicated by Doppler shifts in the spectrum)

A spectroscopic binary (SB) is a binary star system which appears to be a single point of light, but for which movement of one of the pair is detectable by noting Doppler shifts in the spectrum indicating movement to and from the observer, showing the cycle of motion characteristic of an orbit. It is one of a number binary-star classes based upon how the star is determined to be binary. Others:

A double-line spectroscopic binary (SB2) is one where a shifting spectral line can be seen for each star. A single-line spectroscopic binary (or single-lined spectroscopic binary or SB1) is one where shifting lines are seen only for one of the two stars, i.e., one star is so bright that the other cannot be distinguished. Detection of the latter is identical to a single star with an extra-solar planet detected through the radial velocity method, and some effort is necessary to distinguish the two.

(star type,binary star type,spectrography)
Further reading:

Referenced by pages:
astrometric binary
binary star
CfA digital speedometer
double-line spectroscopic binary (SB2)
eclipsing binary (E)
spectrum binary
stellar parameter determination
visual binary
WR 140