The Vibrant, Colorful Ending Of A Dying Star Leaves Behind A Hot Glowing White Dwarf
A dying star ends its life by generating outer layers of gas and expels most of its outer material, which creates into a planetary nebula. This material that is ejected has various colors depending on its composition such as blue-green oxygen and red nitrogen and hydrogen. This can be seen in the above photo taken by NASA/ESA Hubble Space Telescope.
A burned-out star or also referred to as the white dwarf is what stars like the Sun turn out to be after they have consumed their nuclear fuel. It expelled most of its outer material and only the hot core of the star remains, which becomes a very hot white dwarf. This has a temperature greater than 100,000 Kelvin. The white dwarf cools down for more than the next billion years or so if there is an accreting matter from a nearby star, according to NASA.
In the image above, the planetary nebula is called NGC 2440. Its white dwarf at the center has a surface temperature of over 360,000 degrees Fahrenheit (200,000 degrees Celsius), which is one of the hottest known. The NGC 2440 lies about 4,000 light-years from Earth in the path toward the constellation Puppis.
Meanwhile, a typical white dwarf is half as massive as the Sun but quite larger than Earth. Earth has an average density of only 5.4 x 10ᶟ kg/mᶟ, while the Earth-sized white dwarf has a density of 1 x 10⁹ kg/mᶟ. This means that a white dwarf is about 200,000 times as dense and makes it one of the densest collections of matter.
According to Science Daily, the nebula's chaotic structure indicates that the star cast off its mass episodically and it expelled the material in various direction. The nebula has ample clouds of dust, which form long, dark streaks that are pointing away from the star.