Question

Supernovas are particularly useful as distance indicators because:

A) They emit unique patterns of radio waves.
B) They have a constant brightness.
C) Their luminosity can be calibrated based on spectral lines.
D) They are always located in the outer regions of galaxies.

Answer 1

Type Ia supernovae are useful as distance indicators because their luminosity can be calibrated based on spectral lines, making them consistent and reliable standard bulbs for astronomers. They can be seen at very large distances, allowing astronomers to determine distances on a large scale beyond our own galaxy.

Step-by-step explanation:

Type Ia supernovae are particularly useful as distance indicators because their luminosity can be calibrated based on spectral lines. Observations show that supernovae of this type all reach nearly the same luminosity at maximum light, making them consistent and reliable standard bulbs for astronomers. Additionally, type Ia supernovae can be seen at very large distances, allowing astronomers to determine distances on a large scale beyond our own galaxy.