Question

____ are 1000 times more luminous than ____ and are useful to greater distances.

a) Supergiants; main-sequence stars
b) White dwarfs; brown dwarfs
c) Blue giants; red dwarfs
d) Quasars; pulsars

Answer 1

Supergiants are 1000 times more luminous than main-sequence stars, which makes them useful for astronomical observations over great distances.

Step-by-step explanation:

The answer to the question is a) Supergiants; main-sequence stars. Supergiants are 1000 times more luminous than main-sequence stars and are useful to greater distances. This is evident from the luminosities that supergiants can possess, which make them stand out in the cosmos; for instance, type Ia supernovae are especially luminous events involving the explosion of a white dwarf, reaching immense levels of luminosity. Additionally, the comparison between supergiant stars and the Sun, which is a main-sequence star, shows that supergiants are much larger and more luminous.