Astronomy Picture of the Day
The Cat’s Eye Nebula
The Cat’s Eye Nebula or NGC 6543, is a planetary nebula discovered by William Herschel on February 15, 1786. It is found in the constellation of Draco. A Planetary Nebula is formed when a smaller star (around the size of our Sun) dies forming a white dwarf (which is very dense) while the the outer layers of the star are expelled by strong stellar winds. There are around 3000 planetary nebulae known to exist in our galaxy, the Milky way, which has around 200 billion stars. They are rare and are found mostly near the plane of the Milky Way mainly near the galactic center.
The Hubble Space Telescope observations of the Cat’s Eye nebula reveal very complex and interesting structural features. There is a bright and hot White Dwarf in the center of the Cat’s Eye and around 1000 years ago this star lost its outer envelope, producing the nebula. Planetary nebulae are generally faint objects; none are visible to the naked eye.