Taken with my Connectix b&w cooled webcamera in prime focus of my VIXEN VC200 CT (no-guiding) exposuretime: 18 sec (18 sec. x 51 images) used software: QCV2E for cameracontrol and Astroart for processing (elevation of about 20°) 16-08-2001 - Erik Bryssinck - ANTARES Sint-Niklaas
When a star like our sun has used up all its central nuclear fuel, it finally ejects a significant portion of its mass in a gaseous shell which is then visible in the light emitted due to high-energy excitation by its extremely hot central star, which previously was the core of the stellar progenitor (thus, planetary nebulae are a special kind of emission nebulae). These nebulae quickly expand and fade while their matter is spread in the interstellar surroundings.
Erik Bryssinck - 16/08/2001 - ANTARES Belgium
Planetary nebulae are shells of gas thrown out by some stars near the end of their lives. Our Sun will probably produce a planetary nebula in about 5 billion years. They have nothing at all to do with planets; the terminology was invented because they often look a little like planets in small telescopes. A typical planetary nebula is less than one light-year across. (M 57 shown)
