RBA's Astrophotography

Cassiopeia, The W

Posted: November 6th, 2010

Click here for a larger version

Get a poster, t-shirt, mug, mousepad... with this image!

When I was a kid, the first constellation that called my attention wasn't Orion or the Big Dipper. It was Cassiopeia, the "W", and I would immediately go look for it and recognize it. Cassiopeia wasn't my early call into astronomy, but for a while it was the only reason for me to look up at the night sky from a light polluted city in southern Spain "Look, there's Cassiopeia!"... Well, maybe it was some sort of an early call...

This past week, during four different outings at three different sites and around 550 more miles in my SUV, I managed to capture this beautiful "starscape".

There's no better way to (hopefully) enjoy this image but at the largest resolution possible. And while the large image linked above is over 5600 pixels wide, it is still 1/2 of its original resolution, but I felt I had to reduce its size to avoid producing a JPEG over 12mb even at 55% quality (which is already quite degraded). The large image linked above weights almost 6mb (that's at 60% quality), so if you have a slow connection, be aware of that.

It's not a picture of some gorgeous and prominent celestial structures such as nebulae, galaxies, etc. but it's a very special image for me. I hope you enjoy it!

It may seem a simple image to capture and process, but processing was a bit challenging indeed. First, it's a 3x2 mosaic, so all the challenges associated with mosaics apply here - resolved with more or less fortune. Also, getting the subtle - but real - changes in background illumination took some work. Except for the darker areas, that are more prominent in part because of the "lack" of stars, you'll notice that areas with a brighter background don't really have more or less stars than other areas with a slight darker background, and pulling these background illumination differences with a swarm of stars in front can be tricky.

I find it's rather interesting to surf around the image looking for star clusters, and of course, there are plenty of them. Some people may feel that the Gamma Cas and Pacman nebulae could have been selectively processed to become more prominent, or perhaps more detailed, but although any field swarmed by stars can get in the way of other features and often times our goal is to give way to the dust or gas rather than the stars, I think it's obvious that the stars and nothing else are indeed the protagonist of this image.. Why let anything else steal the show?

Here's a small version showing the famous W asterism:



frank (Contact, Page), July 1st, 2011, 5:14
Absolument superbe, magnifique !

Greg Parker (Contact, Page), July 8th, 2011, 0:52
Why hasn't this been an APOD? I don't think I've ever seen the full extent of the Gamma Cass nebulosity in an image before. Great work (and you beat me to it - I am working on a high resolution Cassiopeia too - including, the Double Cluster and Heart & Soul off to the left),

Post a comment
Your name:
Email: (we don't share this!)
Your web site:  (if you have one)

(you have 1000 characters left)