Thursday, August 23, 2007

M27 in CMYK

Here is a new image of Messier 27, done with my new set of Edmund dichroic cyan, magenta, and yellow imaging filters. An alternative to the traditional red, green, blue method, the CMY method has the advantage of allowing more than one color channel through the filter at once making imaging time less critical. At least, that is what it is touted for. This is my first CMY image, and it does appear to do just that. With the old RGB filters, it seemed all I could ever get was red/blue and the green channel was notoriously difficult to get signal with. There are very few, if any, green objects in space, so it would seem that the green color channel is a waste of exposure in many cases. The Cyan filter has both green and blue in its spectral wavelentghs, and in fact pulls in the entire OIII spectral line, which is missed by the old RGB method as this line lies between the blue and green filters.

These filters can be obtained from Edmund Optics and run about $68 dollars a set unmounted.

Yes, they are parfocal! However, I do not believe they block IR.
This image was done using my DSI Pro CCD that I normally use for guiding.

Tuesday, August 14, 2007

The Veil

This is a picture of a portion of the Veil Nebula, a large supernova remnant located near the constellation Cygnus. This object was created when a massive star exploded millions of years past, and threw off large quantities of gases, "star stuff", and shock waves. There are several portions of this visible in the sky, and they all form a roughly circular ring in the lower half of Cygnus. They cover too large an area to take all of them in, unless using a very wide field camera lens for your photo.

These interstellar shock waves will dissipate in several million years as they expand.

Monday, August 13, 2007

The Cocoon

Here is an image of Caldwell 19, the Cocoon Nebula. It is a large cloud of gas and dust superimposed over a dark nebula. The long, dark division among the stars is a black cloud of obscuring dust blocking out the stars behind. This nebula is quite dim, and is very hard to see with the eyes, even through a large telescope.