Main Characteristics of Red Giants and White Dwarfs

Red Giants: Red giants are massive stars in the later stages of their evolution. They are formed when a star runs out of hydrogen fuel in its core and starts burning helium. This causes the outer layers of the star to expand, becoming cooler in temperature but brighter in overall luminosity. Red giants are known for their large size, sometimes expanding to hundreds of times the size of the Sun. They are relatively cool stars with surface temperatures ranging from 2,600 to 4,000 Kelvin. One of the main characteristics of red giants is their eventual fate of shedding their outer layers to form a planetary nebula, leaving behind a dense core known as a white dwarf.

White Dwarfs: White dwarfs are the remnants of stars like our Sun after they have exhausted all their nuclear fuel. They are incredibly dense objects, with masses comparable to that of the Sun but packed into a volume comparable to that of Earth. White dwarfs are very hot, with surface temperatures typically around 8,000 to 40,000 Kelvin. Their ultimate fate is to cool down over billions of years, eventually fading into black dwarfs. White dwarfs are important in the study of stellar evolution as they represent the final evolutionary stage for most stars.