spectral type

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Related to spectral type: Luminosity class

spectral type


spectral class

(Astronomy) 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

spec′tral type′

a category for classifying a star according to features of its spectrum that indicate its surface temperature and chemical composition.
References in periodicals archive ?
It's a bright A-type star, and RSpec's author warns users to begin with a star of that spectral type. These stars display strong hydrogen Balmer lines, which are useful for calibrating the program.
Tauri star RY Tau, the spatial distribution of early spectral type magnetic stars, the effect of high excitement level on the hydrogen ionization and recombination rates, detecting low-amplitude photometric variability in magnetic white dwarfs, and prototyping a moderate-resolution holographic spectrograph.
A solar twin should have a temperature, mass, and spectral type similar to our Sun.
Some of their features allow us to evaluate changes in the star's fundamental parameters compared to those at the visual minimum (spectral type B1, [T.sub.eff] = 22000 [+ or -] 5000 K, log L/[L.sub.[dot encircle]] = 5.5 [+ or -] 0.2, [3]).
"Furthermore, during this period of less than three minutes the star underwent an abrupt change from spectral type M to B; in other words, it went from a temperature of 2,800 kelvin (K) to six or seven times more than that," he stated.
The V-Rc colour index of 0.326 as measured by TB, as well as that of 0.315 derived from 2MASS (see remarks about Table 2, above) indicate a blended spectral type of around F2 and temperature ~7000 K.
I picked these based on the experience of other astronomers and knowledge of the variability with stellar spectral type. This was not a perfect technique.
However, as noted by Koen, its reported spectral type A2 is late for a SPB.
The second half of the report deals with the progress that has already been made towards the resolution of the problem of calibration, particularly the studies aimed at obtaining an initial list of normal stars with reliable spectral type and good visible photometry and that have a high density on the sky.
* December 1967 Potassium Flares "HD 117,043 is a rather ordinary dwarf star of spectral type G6.
The June-July 2016 conference in Prague continued the study of stars with spectral type B and forbidden emission lines in its spectrum--B[e] stars--and related phenomena.
"This term generally refers to dwarf stars with a spectral type ranging from K5V to M5V."