A nebula is an interstellar cloud of dust, hydrogen, helium, and other ionized gases. Originally, the term was used to describe any diffused astronomical object, including galaxies beyond the Milky Way. The temperature of the gas in the nebula is about 10,000 degrees Celsius, and the central stars of planetary nebulae are among the hottest stars in the Universe, with temperatures in the range of 25,000 to over 200,000 degrees Celsius.
There are five types of nebulae currently known.
(Gallery is currently under construction)
