Photometric parallax: Difference between revisions

Revision as of 18:34, 20 July 2025

Latest revision as of 18:34, 20 July 2025

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Assuming that a star is on the main sequence, the star's [[absolute magnitude]] can be determined based on its color. Once the absolute and [[apparent magnitude]]s are known, the distance to the star can be determined by using the [[distance modulus]]. It does not actually employ any measurements of [[parallax]] and can be considered a misnomer.

For evolutionary stages other than the main sequence, the distance can be determined using a typical absolute magnitude for the star's [[spectral type]] and [[luminosity class]] (e.g. giant or supergiant).<ref name="kaler">{{Cite web |title=Beta Phoenicis |url=http://stars.astro.illinois.edu/sow/betaphe.html |access-date=2024-07-20 |website=stars.astro.illinois.edu}}</ref><ref name=Zsoldos2991>{{cite journal |bibcode=1991A&A...246..441Z |title=Photometry of yellow semiregular variables - &#123;rho&#125; Cassiopeiae |last1=Zsoldos |first1=E. |last2=Percy |first2=J. R. |journal=Astronomy and Astrophysics |date=1991 |volume=246 |page=441 }}</ref>

Unlike the [[stellar parallax]] method, the photometric parallax method can be used to estimate the distances of stars over 10 kpc away, at the expense of much more limited accuracy for individual measurements.