Astrophysics (Index)About

stellar distance determination

(methods by which the distance to a star is determined)

Stellar distance determination uses the shorter cosmic distance ladder methods, i.e., within the Milky Way. Parallax is the certain method up to the angular resolution accuracy of astrometry. Optical observations from opposite ends of Earth's orbit are used to determine the triangle from those two points to the observed star. It is limited by accuracy to nearby stars, currently reaching on the order of a hundred parsecs.

Distances to more distant stars within the Milky Way are estimated using known brightness characteristics of Cepheid variables, and by fitting data to the H-R diagram. In the case of binary stars for which the mass and radius can be determined, this helps the H-R Diagram fitting.

Spectroscopic parallax is also used for stars within the Milky Way. (Despite its word "parallax", it is like parallax only in that it is a means of measuring distance.) It is the identification of the star's spectral type, and estimating a distance from the difference between its expected absolute magnitude and its apparent magnitude.

Further reading:

Referenced by pages:
Gliese-Jahreiss Catalog (GJ)
kinematic distance
main sequence fitting
stellar luminosity determination
stellar parameter determination
Wilson-Bappu effect