spectral type


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Related to spectral type: Luminosity class

spectral type

[′spek·trəl ‚tīp]
(astronomy)
A label used to indicate the physical and chemical characteristics of a star as indicated by study of the star's spectra; for example, the stars in the spectral type known as class B are blue-white, and are referred to as helium stars because the dominant lines in their spectra are the lines in helium spectra.
References in periodicals archive ?
The spectral type during the visual minimum was mainly constrained by the presence of He I lines in emission.
From the final value of T1, assuming the primary is main-sequence, the mass, effective temperature and spectral type of the primary were derived; then q gave those parameters for the secondary.
My students have also participated in comparing results of similar spectral type stars or of normal and peculiar stars with similar effective temperatures (e.g., normal A and metallic lined A stars [29]).
These calibrators are confined to the range K0-M0IIIs, for which the combination of observed airborne and spaceborne spectra have made complete 1.2-35 [micro]m spectral coverage a possibility for at least one bright archetype of each spectral type. These have already supported the needs of OSCIR on the Keck, where a calibrator was required below 6 Jy at 10[micro]m in a particular region of the sky, in OSCIR's specific bands.
W Ursae Majoris stars are members of a class of eclipsing variable stars in which the components are of spectral type late A to mid K; though a recent discovery of Koen and Ishihara (2006) suggest a unique contact binary of spectral type "later" than M4.
All these values suggest a spectral type near F0 if the star is unreddened, however, to give the observed V magnitude a main sequence star of this spectral type would lie at a distance of some 1500 parsecs.
Its spectral type is a run-of-the-mill M1 or M2, but we see its light severely reddened--and dimmed about 2 magnitudes--by both circumstellar and interstellar dust.
They are presently situated close to the ZAMS on the HR diagram, are of spectral type B--F, and are at a slow mass accretion (SMA) stage in their evolution.
In the case of NGC 40 the central star is a high temperature object with a spectral type of WC 8, so it is likely that this is a high density object.
The document issued by the notary public declares Duran to be the "owner of the Sun, a star of spectral type G2, located in the center of the solar system, located at an average distance from Earth of about 149,600,000 kilometers."
Other hot stars of spectral type O and B in the association, which is estimated to have a remarkably young age of only about 1 million years, include Omicron ([omicron]), Xi ([xi]), 40, X, and AG Persei.
Sirius A is spectral type A, and around two solar masses.