F-type star

astronomy

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June 26, 2026

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F-type stars, also known as Type F stars, are a classification of stars characterized by a surface temperature of approximately 7,000 kelvins. They fall within the spectral sequence O, B, A, F, G, K, M, which orders stars from hottest to coolest. F-type stars exhibit stronger hydrogen lines in their spectra compared to cooler stars, and these lines become weaker in hotter A-type stars. The Sun, for comparison, is a G-type star. F-type stars are typically found on the main sequence of the Hertzsprung-Russell diagram, which plots stars' intrinsic brightness against their spectral types. Polaris is an example of a Type F star.12345

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Cepheid variable
Most are spectral type F (moderately hot) at maximum luminosity and type G (cooler, Sun-like) at minimum. The prototype star is Delta Cephei, the variability of which was discovered by John Goodricke in 1784. In 1912 Henrietta Leavitt of Harvard Observatory discovered the aforementioned period-luminosity relationship of the…
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Most are spectral type F (moderately hot) at maximum luminosity and type G (cooler, Sun-like) at minimum. The prototype star is Delta Cephei, the variability of which was discovered by John Goodricke in 1784. In 1912 Henrietta Leavitt of Harvard Observatory discovered the aforementioned period-luminosity relationship of the…
Read More

star
Classification of spectral types
In stars of spectral type F, the lines of neutral atoms are weak relative to those of ionized atoms. The hydrogen lines are stronger, attaining their maximum intensities in A-type stars, in which the surface temperature is about 9,000 K. Thereafter, these absorption lines gradually fade as the hydrogen…
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In stars of spectral type F, the lines of neutral atoms are weak relative to those of ionized atoms. The hydrogen lines are stronger, attaining their maximum intensities in A-type stars, in which the surface temperature is about 9,000 K. Thereafter, these absorption lines gradually fade as the hydrogen…
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stellar classification
F-type stars are yellow-white, reach 6,000–7,400 K, and display many spectral lines caused by metals. The Sun is a class G star; these are yellow, with surface temperatures of 5,000–6,000 K. Class K stars are yellow to orange, at about 3,500–5,000 K, and M stars…
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F-type stars are yellow-white, reach 6,000–7,400 K, and display many spectral lines caused by metals. The Sun is a class G star; these are yellow, with surface temperatures of 5,000–6,000 K. Class K stars are yellow to orange, at about 3,500–5,000 K, and M stars…
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