M51, again...

M51, The Whirlpool Galaxy. This is a stack all the sets of subs which were of the same orientation, then subjected to the normal Photoshop treatment of stretching dynamics & c. Unfortunately, When I started this venture, I wasn't keeping a record of what angle I was mounting the camera and similar details, so I can't always add new stacks to old ones. The photo of my scope below is not meant for people to see; instead I am now including a snapshot of the setup used each night so that when I shoot the same object later, I have the scope and camera mounted the same.

The haziness around the upper part of the object is not noise; that is actually the traces of the disk of the upper galaxy. M51 is actually two galaxies; the main spiral, also called M51A or NGC 5194, and NGC 5195 or M51B. M51B is actually completely behind the spiral; they are very close, but not touching. The effects of M51B passing so close is responsible for the well-defined spiral arms of M51A, and wave fronts of dust being pulled along by the smaller galaxy are responsible for those blue knots, where large amounts of star formation are underway. These images from Hubble and Spitzer show not only the things that are just hinted at in my picture, but the sheer amount of star formation going on as a result of the encounter; this thing is on fire. My pics will tend to be much bluer; digital cameras have an infrared filter built in, since for regular photography IR is bad, but it does make my camera more sensitive to blue light. There is a modification available for the camera, but it's in imperfect solution; for now, I'll live with colors that aren't as accurate and vivid as what Hubble takes, knowing that my setup was somewhat more affordable.

While this image is certainly something I am proud of, the ways to improve it are simply screaming at me...I don't believe I can do much better using 30 second exposures. Those pixels that only receive occasional photons, even when those photons are ones I want, are too hard to sort from the noise, and they get dropped in the stacking process. So by adding more subs to this set, I might make it cleaner, but it won't improve the resolution or level of detail.

On the other hand, I am still thrilled and surprised by what I am able to produce-when Lord Rosse first drew his now-famous sketch of M51, showing for the first time that some nebulae had a spiral structure, this is what he drew. That was looking through a 72" reflector, in so many ways identical to my own scope. (Take a look at the Wikipedia article about Lord Rosse and his telescope; it's fascinating. At the time, he couldn't know that the light he saw had taken 31 million years to reach him (and was spared the headaches such numbers can cause!), and also did not know it was an entire island universe, like our own Milky Way. In fact, to this day we still refer to any non-star-like object in the sky as a nebula, which means cloud, whether it is one or not.But in anything but the largest scopes, faraway galaxies and nearby dust clouds often are very similar in appearance; only photographs make the distinction relevant.

So there is is-I've decided that now I need to make my mount cope with 60 second exposures, without having to toss half the subs due to gearing problems.