Helix Nebula

Helix Nebula

About Nebula:

     The Helix nebula is also known as New General Catalogue 7293. It is a planetary nebula which can be located in the constellation of Aquarius in the night sky and it is the nearest nebula to our earth. It was first discovered by famous astronomer Karl Ludwig Harding in 1824 (approx). It's estimated distance from earth is about 700 light year and it looks like a Cat's eye. The physical characteristics of this nebula is similar to the Dumbbell Nebula. Due to the Cat eye appearance, sometimes it is referred to as the Eye of God. 

Location and Age:

The Helix nebula is located in the Aquarius constellation and it lies about 700 light years away from our earth which spans at a rate of 0.8 parsecs. Scientist estimated the current age of the nebula is about 10,600 +2300 or -1200 years with a expansion rate of 31 km per second.

Physical Structure:

NGC 7293

     The structure of the helix nebula is prolate spheroid and it was estimated that the expansion would have occurred in past 6,560 years and 12,100 years for the expansion of inner disk. Data from the spectroscopic studies reveal that the outer ring expansion rate is 40 km per second and the inner disk expansion rate is 32 km per second. It has many cometary knots and it was the first nebulae discovered to contain this. There are more than 20,000 cometary knots are estimated to be in the Helix. The temperature range increases from outer disk to the inner disk at the rate of 900 Kelvin to 1800 Kelvin.

Tags: Orion Nebula | Bow-Tie Nebula | Ornament Nebula | Tarantula Nebula | IC418 Nebula | Magellanic Nebula 

Image Credit : NASA's Hubble Space Telescope

Text Credit : Wiki and Team Fornax