Select the correct location for the dwarf planets in the solar system

Which is the classification given to a galaxy with a small nuclear bulge, and loosely wound arms with no bar through the nuclear bulge?  

The masses of stars are determined through the study of?

Label the layers of the Earth’s atmosphere using the diagram below

A star’s lifetime, luminosity, and eventual fate is determined by

What would happen to the Earth if the sun suddenly became a black hole? (ignore the temperature change)

Extremely high mass (20-30 solar masses) stars have large cores. When they die they will most likely end up as a

The least dense planet in the solar system is

There is star formation in Elliptical Galaxies.

List the Spectral types in order of temperature from Hottest to Coolest.