Helix Nebula (NGC 7293)

clic for 40% size 1200 x 952 (225 kB)

clic for 70% size 2020 x 1603 (550 kB)

About this Image

The Helix Nebula is a vast glowing cloud of Hydrogen, Nitrogen, Oxygen, and other elements some 500 light years away toward the constellation Aquarius and spans about 2.5 light-years. The nebula is made up of gas ejected from a blueish dying star, which is located in the center of the nebula.
The center part of the nebula shows many of drop-like "knots," which are formed when hot gas thrown off from the surface of the star collides with the cooler surrounding material. These knots emanate from the star in a radial pattern, each one stretching for about 100 billion miles.

The Helix Nebula is one of the closest and so one of the apparently largest planetaries known: Its apparent size covers an area of 16 arc minutes diameter; it's halo extends even further to 30 arc minutes (almost the moon's apparent diameter). It is an example of a planetary nebula created at the end of the life of a Sun-like star. The outer gases of the star expelled into space appear from our vantage point as if we are looking down a helix.

The remnant central stellar core, destined to become a white dwarf star, glows in light so energetic that it causes the previously expelled gas to fluoresce.

Further information:
Extended emissions around the Helix: 1.
Helix structure and knots: 2.
Creation of the Helix: 3.
North is up.

Below you see a crop of the center at 60/100% size.

clic for 100% size 1170 x 998 (210 kB)

Technical Details


TEC-140 APO refractor with TEC flattener at f/7

Mount AP-400 GEM
Camera SBIG STL-11000M at -25C, internal filter wheel
Filters LRGB
Date May 27-29, 2006.
Location Hakos/Namibia
Sky Conditions mag 6.5, high transparency, temperature 10 C,
Exposure Ha:L:R:G:B= 180:180:60:60:60 min
(10 min sub-exposures for LRGB, 30 min subs for Ha)
all 1x1.
Processing Image aquisition and calibration in Maxim DL 4.11;
Photoshop: curves, color balance;