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

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

Most stars are grouped into a small number of spectral types. 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 are the classes of stars?

Harvard spectral classification

Class Effective temperature Fraction of all main-sequence stars
A 7,500–10,000 K 0.6%
F 6,000–7,500 K 3%
G 5,200–6,000 K 7.6%
K 3,700–5,200 K 12.1%

What are the 5 classes of stars?

The Different Types of Stars

  • Protostar. A protostar is what comes before a star has formed – a collection of gas that collapsed from a huge molecular cloud.
  • T Tauri Stars.
  • Main Sequence Stars.
  • Red Giant Stars.
  • White Dwarf Stars.
  • Red Dwarf Stars.
  • Neutron Stars.
  • Supergiant Stars.

What are the 6 main star types?

Exploring the stars: Six star types you should know about

  • We are familiar with the idea that the twinkling pinpricks of light in the sky are stars, like our own Sun.
  • Solar-type Stars.
  • Hot Blue Stars.
  • Red Dwarf Stars.
  • Red Giant Stars.
  • White Dwarfs.
  • Neutron Stars and Black Holes.

What is the hottest type of Sun?

Eta Carinae could be as large as 180 times the radius of the Sun, and its surface temperature is 36,000-40,000 Kelvin. Just for comparison, 40,000 Kelvin is about 72,000 degrees F. So it’s the blue hypergiants, like Eta Carinae, which are probably the hottest stars in the Universe.

Which star is the coldest star?

brown dwarf
According to a new study, a star discovered 75 light-years away is no warmer than a freshly brewed cup of coffee. Dubbed CFBDSIR 1458 10b, the star is what’s called a brown dwarf.

What color is the hottest star on the HR diagram?

Stars on the Main Sequence that are hotter than the Sun are also larger than the Sun. So hot blue stars are more luminous (and therefore appear higher in this diagram) for two reasons: they are hotter, and hot objects are more luminous than cool objects, but they are also larger.

What is the coolest spectral class of stars?

Using this system, blue stars are the hottest, and are called O-type. The coolest stars are red and are called M-type. In order of increasing temperature, the spectral classes are M (red), K (orange), G (yellow), F (yellow-white), A (white), B (blue-white), O (blue).

What does spectral class mean?

spectral class. n. (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.

What are stellar classes?

In human astronomy, stellar classification was a classification of stars based on their spectral characteristics. The spectral class was the designated class of a star, describing the ionization of its chromosphere, what atomic excitations were most prominent in the light, giving an objective measure of the temperature in this chromosphere .

What does the spectral class letters mean?

The spectral class of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere’s temperature. Most stars are currently classified under the Morgan-Keenan (MK) system using the letters O, B, A, F, G, K, and M , a sequence from the hottest ( O type) to the coolest ( M type).