Class A
Our Sun has a spectral class of G2V.
Spectral class is classification of stars by their external features..Like light,temperature etc..
Class O
K (orange )
Alpha Centauri A - It is 4.365 light years away and has a spectral class of G2V the same as our Sun
Sirius is a double star. The brighter component ... the one you actually notice in the night sky ... is spectral class A1V. The faint 'secondary' component is spectral class DA2.
Sirius A has a spectral type of A1V. So it has a colour of white to white blue.
The spectral lines of Sirius are blueshifted because the star is moving more or less toward us.
Sirius is a binary star. Sirius A has a spectral type of A1V and will appear on the HR in the top left corner. Sirius B has a spectral type of DA2 and will appear on the HR in the bottom left corner as a white dwarf.
The spectral class is A0Va.
Our Sun has a spectral class of G2V.
Antares has a spectral class of M1LB.
Spectral class Y, which is typical of "brown dwarf" stars.
Spectral class is classification of stars by their external features..Like light,temperature etc..
Sirius is a binary star system Sirius A and Sirius B.The distance separating Sirius A from B varies between 8.1 and 31.5 AU. (See related question).
Sirius is a binary system, that appears as a single star from EarthSirius A has an absolute magnitude of 1.42Sirius A has an apparent magnitude of -1.46Sirius B has an absolute magnitude of 11.18Sirius B has an apparent magnitude of 8.3See related question for the difference between absolute and apparent.
Sirius B is a white dwarf and has a spectral type of DA2. As it is a white dwarf, it is cooling all the time. It's current temperature is about 25,200 K