spectral type

noun

, Astronomy.

1. a category for classifying a star, as A star or G star, according to features of its spectrum, as its shape as a function of temperature and wavelength and its absorption spectrum, that indicate the surface temperature of the star and the presence of particular atoms or molecules in its outer layers: principal types are spectral types O, B, A, F, G, K, and M.

spectral type

noun

1. any of various groups into which stars are classified according to characteristic spectral lines and bands. The most important classification ( Harvard classification ) has a series of classes O, B, A, F, G, K, M, the series also being a scale of diminishing surface temperature

spectral type

1. A classification system for stars based on the strength of their spectral lines, using the letters O, B, A, F, G, K, M, L, and T to denote a range from blue (as in blue giant stars) to dim red (as in brown dwarfs). The spectrum of a star correlates with its surface temperature, ranging from over 60,000°K (O type) to less than 3,500°K (L and T types).
2. See also Hertzsprung-Russell diagram

Word History and Origins

Origin of spectral type¹

First recorded in 1920–25

Example Sentences

What makes this finding even more interesting is that HIP 11915 is almost a twin of our Sun, of a similar size and spectral type.

From Forbes

The shots have a Vargas-girl glamour that’s notably different from the spectral type projected by Pomellato’s former face, Tilda Swinton.

From New York Times

The team ran simulations that placed hypothetical Earths around six aging G spectral type stars some 30 light years from Earth.

From Forbes

To seek the Milky Way’s farthest-flung residents Bochanski's team started with nearly seven million stars, using near-infrared data to select those whose colors match spectral type M, which designates stars that are cool and red.

From Scientific American

Near the end of its life a star like the sun expands and cools; our sun will become a yellow giant of spectral type G and then an orange giant of type K before turning into a cooler red M giant.

From Scientific American