What are the luminosity classes?

What are the luminosity classes?

Luminosity classes are labeled with Roman numerals from I to V: I are supergiant stars, II are bright giants, III are ordinary giants, IV are subgiants, and V are ordinary main sequence stars.

What type of star is b0 V?

A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars are extremely luminous and blue.

What is the spectral class classes of a white dwarf?

Luminosity class 0 or Ia+ is used for hypergiants, class I for supergiants, class II for bright giants, class III for regular giants, class IV for subgiants, class V for main-sequence stars, class sd (or VI) for subdwarfs, and class D (or VII) for white dwarfs.

What are hot B-type stars?

The hot B-type stars, such as Epsilon Orionis, are characterized by lines of helium and of singly ionized oxygen, nitrogen, and neon. In very hot O-type stars, lines of ionized helium appear.

What does luminosity class tell us?

Luminosity Class: describes the region of the HR diagram in which the star falls; luminosity class is more closely related to its size than to its luminosity (I=supergiants. II=Bright giants, III=Giants, IV=Subgiants, V=Main sequence stars).

What are the 7 spectral classes in order from hottest to coolest?

The Henry Draper Catalogue and the Bright Star Catalogue list spectral types from the hottest to the coolest stars (see stellar classification). These types are designated, in order of decreasing temperature, by the letters O, B, A, F, G, K, and M.

What luminosity class is the sun?

To completely describe the star, the MK luminosity class is appended to the original Harvard classification for the star. For example, our Sun is a main sequence G2 star, therefore its full classification is G2V.

What class is our Sun?

class G star
The Sun is a class G star; these are yellow, with surface temperatures of 5,000–6,000 K. Class K stars are yellow to orange, at about 3,500–5,000 K, and M stars are red, at about 3,000 K, with titanium oxide prominent in their spectra.