Spectroscopic parallax or main sequence fitting[1] is an astronomical method for measuring the distances to stars.
Despite its name, it does not rely on the geometric parallax effect. The spectroscopic parallax technique can be applied to any main sequence star for which a spectrum can be recorded. The method depends on the star being sufficiently bright to provide a measurable spectrum, which as of 2013 limits its range to about 10,000 parsecs.[2]
To apply this method, one must measure the apparent magnitude of the star and know the spectral type of the star. The spectral type can be determined by observing the star's spectrum. If the star lies on the main sequence, as determined by its luminosity class, the spectral type of the star provides a good estimate of the star's absolute magnitude. Knowing the apparent magnitude (m) and absolute magnitude (M) of the star, one can calculate the distance (d, in parsecs) of the star using (see distance modulus). The true distance to the star may be different than the one calculated due to interstellar extinction.[3]
The method ultimately derives from the spectroscopic studies of sunspots and stars by Walter Sydney Adams and Ernst Arnold Kohlschütter.[4]
The method is an important step on the cosmic distance ladder.
^Carroll, Bradley W.; Ostlie, Dale A. (2017). An introduction to modern astrophysics (Second ed.). Cambridge, United Kingdom. p. 475. ISBN 9781108422161.{{cite book}}: CS1 maint: location missing publisher (link)
^Cite error: The named reference esa was invoked but never defined (see the help page).
^Cite error: The named reference seeds was invoked but never defined (see the help page).
^Cite error: The named reference trimble was invoked but never defined (see the help page).
and 27 Related for: Spectroscopic parallax information
Spectroscopicparallax or main sequence fitting is an astronomical method for measuring the distances to stars. Despite its name, it does not rely on the...
distance measurements in astronomy come from trigonometric parallax, as applied in the stellar parallax method. As the Earth orbits the Sun, the position of...
1900–1930: first catalogued. After 1930: earliest trigonometric or spectroscopicparallax. Panuzzo, P. (2024). "Discovery of a dormant 33 solar-mass black...
limited accuracy for individual measurements. Parallax in astronomy Spectroscopicparallax Dynamical parallax Mario Juric; et al. (2008). "The Milky Way...
again. Such stars are known as single-lined spectroscopic binaries ("SB1"). The orbit of a spectroscopic binary is determined by making a long series...
Telescope and infrared color–magnitude diagram fitting (so-called "spectroscopicparallax") favor a distance between 135 and 140 pc; a dynamical distance...
accuracies within 5% can be achieved. Parallax in astronomy Photometric parallax method Spectroscopicparallax Patrick Moore (2002). Philip's Astronomy...
doi:10.1086/148230. Wyller, A. A. (December 1957). "Parallax and orbital motion of spectroscopic binary Polaris from photographs taken with the 24-inch...
features in an H–R diagram of another set of stars, a method known as spectroscopicparallax or main-sequence fitting. Since globular clusters form at once from...
extraterrestrial intelligence (SETI) Stellar parallax Allende Prieto, C.; et al. (June 2004), "S4N: A spectroscopic survey of stars in the solar neighborhood...
century as a high-velocity star based on its proper motion. An early spectroscopic analysis by Joseph W. Chamberlain and Lawrence Aller revealed it to...
Calculated using a parallax of 84.27 milliarcseconds in the equation: 1/(Parallax (arcsec)) = distance (parsecs) Calculated using a parallax of 72.5167 milliarcseconds...
The distance derived from the Hipparcos satellite parallax is 212±30 parsecs, while spectroscopic distances, comparisons to similar stars, and cluster...
Vir or α Vir. Analysis of its parallax shows that it is located 250±10 light-years from the Sun. It is a spectroscopic binary star and rotating ellipsoidal...
astrometric observations (for example, a secular change in the annual parallax). Light from an object with a substantial relative radial velocity at emission...
and all have significant margins of error. The original derivation of a parallax using measurements from the astrometric satellite Hipparcos gave an uncertain...
close enough to have accurate parallax measurements as well as distance estimates by more indirect means. The Hipparcos parallax for γ2 implies a distance...
system can be seen by large telescopes, and the brighter of the two is a spectroscopic binary. These three stars are all blue-white main-sequence stars, each...
parallax and total proper motions (how far they move across the sky due to their actual velocity relative to the Sun), along with spectroscopically determined...
approximately 123 light years from the Sun, based on parallax measurements. It is a spectroscopic binary made up of the stars designated α Ursae Majoris...
Centaurus and the eleventh brightest star in the night sky. According to parallax measurements from the astrometric Hipparcos satellite, the distance to...
Based upon parallax measurement, Epsilon Cygni is about 73 light-years from the Sun. The system has three constituents: a spectroscopic binary (designated...
measures Delta Cephei's parallax (distance). The outer visual companion Delta Cephei C (HD 213307) may also be a spectroscopic and astrometric binary....
through parallax measurements, use of standard references such as cepheid variables or Type Ia supernovas, or redshift measurement. Spectroscopic redshift...