A-type star

Astrophysics (Index)

About

(A, A-class star) (star with spectral characteristics of around 8500 K)

An A-type star is a star within the A-class, a spectral class indicating stars with strong hydrogen absorption lines, a white color and a surface temperature in the range of 7,500 to 10,000 K. The spectral energy distribution peaks in the visible/near ultraviolet range. Main sequence stars of this class are on the order of 2 solar masses, 2 times solar radius and 10 times as bright as the Sun. Such main sequence stars burn their hydrogen on the order of a billion years. Characteristics of A-type main sequence stars:

1.4-1.8	radius(solar)
1.4-2.1	mass(solar)
1.5-2.4	absolute magnitude(visual)
5-25	bolometric luminosity(solar)
1.5-4 billion years	main-sequence lifetime
0.6%	abundance

Example A-type stars are Canopus (a supergiant), HR 8799, Sirius A and Vega.

WaveL	Freq	Photon Energy
145nm	2.1PHz	8.6eV	begin	A-type star
290nm	1.1PHz	4.3eV	end	A-type star