September 29, 2007

NGC 7789 September 2007


The nights were beautiful the week of the new moon in September. I had one great night of imaging. Here is one taken toward the end of the night. I was waiting for the Pleiades to come up over the trees, and was too tired to think of another target than this one, a visual favorite. The cluster NGC 7789 in Cassiopeia is too large to shoot with the DSI Pro at a 720mm focal length (the Pleiades are even larger, and I didn't even try), but I aimed well within NGC 7789's borders and started shooting, anyway. The stars in this shot are within the cluster. I think they are lovely. Yes, they need color. I will get to that, eventually, but I am still so amazed to see these images, even in black and white, that I just haven't bothered yet. The scope was the Vixen R135S, at f/5.3, unguided on the LXD75. This is 11 minutes 16 seconds worth of 4-second exposures processed in Registax.

2 comments:

Unknown said...

What is the name of the 'hook' shaped line of stars in this photo. Isn't it like 'the Coathanger' or something? Or am I thinking of something else entirely?

Polaris B said...

That's the shape, alright. One of the reasons I like this cluster is because it has several hooks in it. Notice there is another one up on the top left corner. This image sits on the cluster's edge. In the middle of the cluster there are several other arcs, and also several straight lines of stars. It's as if someone had cut a string of pearls into several pieces, then dropped them onto black velvet. Some single pearls also lay strewn about the scene.

What most folks call The Coathanger, though, is an open cluster in Vulpecula. There is a decent photo of it (here.