ATRONOMY – TELLAR PHYIC (48) CALCULATOR
Spectral Type Temperature
A precise tool.
What is the Spectral Type Temperature & How does it work?
Stars are classified by their spectra, which reflect the temperature of their photospheres. The Morgan‑Keenan (MK) system assigns a spectral type (O, B, A, F, G, K, M) and a numeric subclass (0–9) that together indicate the star’s effective temperature.The hottest O‑type stars have surface temperatures exceeding 30,000 K, while the coolest M‑type dwarfs are only a few thousand kelvin. This temperature governs the peak wavelength of the emitted radiation according to Wien’s law.Astronomers often need a quick estimate of a star’s effective temperature from its spectral type. A simple empirical relation approximates the temperature as a function of the spectral class letter.
T_{\mathrm{eff}} \approx T_{0}\,10^{-0.1\,S}
T_{\mathrm{eff}} = effective temperature (K), T_{0} = reference temperature for class O (≈30 000 K), S = subclass index (0 for O, 1 for B, …, 6 for M)
Parameters
Result
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Frequently Asked Questions
What is the temperature range for O-type stars?
O-type stars have surface temperatures exceeding 30,000 K.
How do astronomers determine a star’s temperature from its spectrum?
Astronomers use Wien’s law, which relates the peak wavelength of emitted radiation to the temperature of the star.
What is the coolest type of star in the MK system?
The coolest stars are M-type dwarfs, with surface temperatures of a few thousand kelvin.
Can you explain the numeric subclass in spectral classification?
The numeric subclass (0-9) provides more detailed information about the star’s temperature within its spectral type category.
What does the spectral type ‘G’ represent?
A G-type star, like our Sun, has a surface temperature between 5,000 and 6,000 K.
How is the peak wavelength of radiation related to a star’s temperature?
According to Wien’s law, the peak wavelength of emitted radiation decreases as the temperature increases.
What is the significance of spectral classification in astronomy?
Spectral classification helps astronomers understand a star’s temperature, composition, and evolutionary stage.
Results are for informational purposes only and do not constitute professional advice.