Tiers:
S+
For a star to be in S+ Tier, it must have an effective temperature hotter than 100,000 Kelvin.
S
For a star to be in S Tier, it must have an effective temperature hotter than 25,000 Kelvin but colder than 100,000 Kelvin. At the coldest end, stars appear pastel light blue . It must emit light of 115.9 nanometers or less. The absolute magnitude of the star must be less than -5.4. The mass must be greater than 10 solar masses. The radius must be greater than 5.2 solar radii. The luminosity must be greater than 9,700 solar luminosities. The B-V color index must be less than -0.26. The lifetime must be less than 29 million years.
A
For a star to be in A Tier, it must have an effective temperature hotter than 11,000 Kelvin but colder than 25,000 Kelvin. At the coldest end, stars appear pastel light blue . It must emit light of 263.4 nanometers or less, but 115.9 nanometers or more. The absolute magnitude of the star must be less than 0.082 but more than -5.4. The mass must be greater than 2.9 solar masses but must be less than 10 solar masses. The radius must be greater than 2.4 solar radii but less than 5.2 solar radii. The luminosity must be greater than 82 solar luminosities but less than 9,700 solar luminosities. The B-V color index must be less than -0.077 but more than -0.26. The lifetime must be more than 29 million years but less than 700 million years.
B
For a star to be in B Tier, it must have an effective temperature hotter than 7,500 Kelvin but colder than 11,000 Kelvin. At the coldest end, stars appear Tr. Flu. Blue . It must emit light of 386.4 nanometers or less, but 263.4 nanometers or more. The absolute magnitude of the star must be less than 2.3 but more than 0.082. The mass must be greater than 1.7 solar masses but must be less than 2.9 solar masses. The radius must be greater than 1.8 solar radii but less than 2.4 solar radii. The luminosity must be greater than 9.3 solar luminosities but less than 82 solar luminosities. The B-V color index must be less than 0.25 but more than -0.077. The lifetime must be more than 700 million years but less than 2.8 billion years.
C
For a star to be in C Tier, it must have an effective temperature hotter than 6,000 Kelvin but colder than 7,500 Kelvin. At the coldest end, stars appear Institutional White . It must emit light of 483 nanometers or less, but 386.4 nanometers or more. The absolute magnitude of the star must be less than 4.2 but more than 2.3. The mass must be greater than 1.1 solar masses but must be less than 1.7 solar masses. The radius must be greater than 1.2 solar radii but less than 1.8 solar radii. The luminosity must be greater than 1.7 solar luminosities but less than 9.3 solar luminosities. The B-V color index must be less than 0.57 but more than 0.25. The lifetime must be more than 2.8 billion years but less than 7.5 billion years.
D
For a star to be in D Tier, it must have an effective temperature hotter than 5,000 Kelvin but colder than 6,000 Kelvin. At the coldest end, stars appear wheat . It must emit light of 579.6 nanometers or less, but 483 nanometers or more. The absolute magnitude of the star must be less than 5.9 but more than 4.2. The mass must be greater than 0.81 solar masses but must be less than 1.1 solar masses. The radius must be greater than 0.76 solar radii but less than 1.2 solar radii. The luminosity must be greater than 0.32 solar luminosities but less than 1.7 solar luminosities. The B-V color index must be less than 0.90 but more than 0.57. The lifetime must be more than 7.5 billion years but less than 17 billion years.
E
For a star to be in E Tier, it must have an effective temperature hotter than 3,500 Kelvin but colder than 5,000 Kelvin. At the coldest end, stars appear warm yellowish orange . It must emit light of 827.9 nanometers or less, but 579.6 nanometers or more. The absolute magnitude of the star must be less than 8.9 but more than 5.9. The mass must be greater than 0.44 solar masses but must be less than 0.81 solar masses. The radius must be greater than 0.39 solar radii but less than 0.76 solar radii. The luminosity must be greater than 0.021 solar luminosities but less than 0.32 solar luminosities. The B-V color index must be less than 1.5 but more than 0.90. The lifetime must be more than 17 billion years but less than 78 billion years.
F
For a star to be in F Tier, it must have an effective temperature hotter than 2,600 Kelvin but colder than 3,500 Kelvin. At the coldest end, stars appear warm yellowish orange . It must emit light of 1.115 micrometers or less, but 827.9 nanometers or more. The absolute magnitude of the star must be less than 13 but more than 8.9. The mass must be greater than 0.08 solar masses but must be less than 0.44 solar masses. The radius must be greater than 0.11 solar radii but less than 0.39 solar radii. The luminosity must be greater than 5.1×10-4 solar luminosities but less than 0.021 solar luminosities. The B-V color index must be less than 2.2 but more than 1.5. The lifetime must be more than 78 billion years but less than 5.5 trillion years.
F-
For a star to be in F- Tier, it must have an effective temperature colder than 2,600 Kelvin. It must emit light of 1.115 micrometers or more. The absolute magnitude of the star must be more than 13. The mass must be less than 0.08 solar masses. The radius must be less than 0.11 solar radii. The luminosity must be less than 5.1×10-4 solar luminosities. The B-V color index must be more than 2.2. The lifetime must be more than 5.5 trillion years.
End States
S+
- Black Hole
S
- Neutron Star
A, B, C, D, and E
- Carbon-Oxygen White Dwarf
F
- Helium White Dwarf
F-
- Unknown since they cannot die.