Helix Nebula (NGC 7293)

Data aquisition by Josch Hambsch, RGB preprocessing by Karel Teuwen

clic for 42% size 1680 x 1120 (352 kB)

clic for 70% size 2800 x 1867 (843 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. 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.

Find a wider view on this nebula here.


Technical Details
Optics

20" cassegrain in corrected primary and secondary focus at f/3 and f/9,

Mount Liebscher GEM
Camera SBIG STL-11000M, internal filter wheel
Filters Astronomik LRGB
Date L: Aug 04, 2008 at f/9, colors from 2007 at f/3.
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 by Josch Hambsch
(10 min sub-exposures for LRGB, 30 min subs for Ha)
all 1x1.
Processing Image aquisition and calibration in Maxim DL 4.5;
Photoshop: curves, color balance;

Thanks to Josch and Karel for providing the raw data!