BRAINCAKEEstimating the Radius of a Star
The radius of a distant star cannot be measured directly, but it can be estimated by combining Wien's displacement law and Stefan's law.
Step 1: measure the peak wavelength λmax of the star's spectrum and use Wien's law to find its surface temperature:
T = 2.9 × 10−3 / λmax
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Key terms in this lesson
- luminosity
- The total radiant power emitted by a star, measured in watts.
More in Astrophysics and Cosmology
- Emission and Absorption Line Spectra
- Using Diffraction Gratings to Analyse Starlight
- Wien's Displacement Law
- Stefan's Law
- The Astronomical Unit, Light Year and Parsec
- Stellar Parallax
- The Cosmological Principle
- The Doppler Effect and Red Shift
All 24 lessons in Astrophysics and Cosmology · All OCR A-level Physics topics