Types of stars ? How they were grouped?
Types of stars? How they were grouped?
Star Classification
Stars are classified by their spectra (the elements that they absorb) and their temperature. There are seven main types of stars. In order of decreasing temperature, O, B, A, F, G, K, and M.
O and B stars are uncommon but very bright; M stars are common but dim...
Hertzsprung - Russell Diagram
The Hertzsprung -Russell (H-R) Diagram is a graph that plots stars colour
· spectral type or surface temperature vs. its luminosity
· intrinsic brightness or absolute magnitude
On it, astronomers plot stars' colour, temperature, luminosity, spectral type, and evolutionary stage.
This diagram shows that there are 3 very different types of stars:
Stars are classified by their spectra (the elements that they absorb) and their temperature. There are seven main types of stars. In order of decreasing temperature, O, B, A, F, G, K, and M.
O and B stars are uncommon but very bright; M stars are common but dim...
Hertzsprung - Russell Diagram
The Hertzsprung -Russell (H-R) Diagram is a graph that plots stars colour
· spectral type or surface temperature vs. its luminosity
· intrinsic brightness or absolute magnitude
On it, astronomers plot stars' colour, temperature, luminosity, spectral type, and evolutionary stage.
This diagram shows that there are 3 very different types of stars:
- Most stars, including the sun, are "main sequence stars," fuelled by nuclear fusion converting hydrogen into helium. For these stars, the hotter they are, the brighter. These stars are in the most stable part of their existence; this stage generally lasts for about 5 billion years.
- As stars begin to die, they become giants and supergiants (above the main sequence). These stars have depleted their hydrogen supply and are very old. The core contracts as the outer layers expand. These stars will eventually explode (becoming a planetary nebula or supernova, depending on their mass) and then become white dwarfs, neutron stars, or black holes (again depending on their mass).