NEBULAS

   A nebula (from Latin: "cloud" pl. nebulae or nebulæ, with ligature or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Originally, nebula was a name for any extended astronomical object, including galaxies beyond the Milky Way. The Andromeda Galaxy, for instance, was referred to as the Andromeda Nebula before galaxies were discovered by Edwin Hubble. Nebulae are often star-forming regions, such as in the Eagle Nebula.

   There are some types of galaxies:

• Emission,

• Reflection,

• Planetary,

• SN remnants.

Credit Image: Emil Ivanov