Planetary Nebula

Probably the most misleading name in astronomy. Planetary nebula have got nothing to do with planets. Back in the old days a famous astronomer called William Herschal named them planetary nebula since they resembled faint cloudy planets. However, in these enlightened days we have a different understanding. When a star runs out of fuel it has a tendency to explode. The size of the bang is related to the size of the star. A star similar to our Sun will, at the end of its days, kick out a layer of its outer atmosphere into a large expanding cloud. This is what a planetary nebula is. Nothing to do with planets. There are many of this class of object within reach of our equipment.

The Dumbbell Nebula M27 was the first planetary nebula ever discovered. On July 12, 1764, Charles Messier discovered this new and fascinating class of objects, and descibed it as an oval nebula without stars. The name "Dumb-bell" goes back to the description by John Herschal, who also compared it to a "double-headed shot."

The Ring Nebula, M57, was discovered by Antoine Darquier de Pellepoix in 1779. It is a ring, or torus, of matter orbiting the central star, which is just visible. We are viewing it from above. If viewed from the side, it might look more like M27.

It's also hard to estimate the distance to these objects, but they are thought to be several thousand light years away. Compare this to the millions of light years to the galaxies on other pages.

M57                                                                         M27

Location Toms back garden, 2 August 2003. No moon. Fair to good transparency.
Statistics About 50 stacked frames of about 15 seconds each. 
Equipment used Helios 8" newtonian reflector Logitech QuickCam Pro 4000 SC Long Exposure Modified (no lens) K3CCDTools, Registax and Photoshop

M57 on the left, M27 on the right. This was the first attempt at these objects, and came out better than expected. Improvements will be attempted. The yellow glow in the top left of M27 is an artifact of imaging, and nothing to do with the object.




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Page last updated 2003-08-21