Astrophysics (Index)About

spectroscopic parallax

(stellar distance determined through spectroscopy)

Spectroscopic parallax is the determination of the distance to a star through spectrography. Like parallax, it offers a means to determine the distance to a star, but the word "parallax" is otherwise unrelated and misleading regarding the method, which is as follows: from a main sequence star's spectrum, its spectral type can be determined, and its absolute magnitude can be estimated. The distance is derived by comparing this to its apparent magnitude. Spectroscopic parallax yields an estimate but there are factors that confound the result: reddening and the differences in absolute magnitude due to stellar factors other than spectral type: age, rotation, composition at time of star formation, companions, etc. It is more useful in studies of multiple stars (e.g., stellar demographicses) than in producing a useful estimate for an individual star.

Further reading:

Referenced by pages:
luminosity distance (dL)
main sequence fitting
standard candle
stellar distance determination