Discovering the Brightest Stars in the Sky!

Which star is more luminous, Rigel or Sirius B? Do they have the same temperature?

Rigel is more luminous than Sirius B, but they have the same temperature.

Which star has the greater surface area?

a) Rigel
b) Sirius B
c) They have the same surface area
d) There is insufficient information to answer this question

Answer:

Option b: Sirius B

The Stefan-Boltzmann law relates the luminosity, radius, temperature, and surface area of a star. If two stars have the same temperature but one is more luminous than the other, we can use this law to determine which star has the larger surface area.

The formula shows that luminosity is proportional to the surface area, so if one star is much more luminous than the other, it must have a larger surface area, L = 4πR²σT^4.

In this case, Rigel is much more luminous than Sirius B, so we can conclude that Rigel has a greater surface area. Therefore, the correct answer is option b: Sirius B.