Mestel's model for the cooling of these objects assumes that the ions in the core are an ideal gas.  
Mestel's model for the cooling of these objects assumes that the ions in the core are an ideal gas.  Types of these objects include Sirius B and Procyon B, both of which lie in the left and middle of the lower part of the HR Diagram. According to one equation, these objects become smaller as their mass increases since they are held together by electron degeneracy pressure. That equation relates how they should have a diameter of 0 at 1.44 solar masses. After its phase as a red giant, the Sun will become one of these stars, since its mass does not exceed the Chandrasekhar limit. For 10 points, name these relatively small and low-luminosity stars whose name indicates their pale color.
Mestel's model for the cooling of these objects assumes that the ions in the core are an ideal gas.  
white dwarf or white dwarves [prompt on just dwarf, on the first sentence prompt on stars, but after it, DO NOT PROMPT or ACCEPT IT]