March 26, 2008

10pm-12:45am

An unexpected session.  The weather was supposed to turn cloudy and rainy in the evening, but the forecasters were wrong.  The sky remained clear; the air cool, but not quite cold.  I set up the scope with the impression that time was of the essence before clouds would move in.  Consequently, I didn't obtain as good a polar alignment as possible, which ultimately limited the number of sub-exposures that could be stacked as the targets kept moving, slowly, out of the FOV.

Also, focus was not refined, again due to perceived time constraints.  The images suffer from that lack of effort. 

M106

I hadn't tackled this galaxy with the DSI Pro just yet and was eager to see how it would handle its large and somewhat amorphous disk.   

The DSI clearly captured the disk, and would have resolved more of it had more sub-exposures been capture and if the focus had been more exacting.  Not a terrible first attempt at it, though.

NGC 4564

For some reason, this has always been a very difficult target to image.  The galaxy is seen edge-on and is very faint, appearing like a ghost in the images.

This image comprises 40, 30-second images.  Tracking is always mysteriously troubled when I try to image this galaxy, and if you notice the stars at the left side of the image, you can see that trouble is evident in this image as well.  Indeed, NGC 4565 had moved so far to the edge of the FOV by the time 40 subs were stacked, that I had to stop the stack right there.

Unsatisfied with the limited number of subs stacked in the previous image, I attempted to stack more subs by lowering the exposure time to 15 seconds.  In this manner I was able to stack about 60 subs before the image slipped out of the FOV.

Despite the difficulties of capturing this image, and its inferior visual appeal compared to other edge-on galaxies, like NGC 891, I intend to return to NGC 4565 in the coming weeks to attempt a much longer imaging of the galaxy.

M99

This is the first attempt at this galaxy with the DSI Pro.  Looking like a smaller version of M101, this also sometimes called the pinwheel galaxy, though its smaller appearance robs it of the grandeur of M101. 

Despite its diminutive size, the spiral arms show clearly in this stack of 80, 30-second images.  As usual, more and longer images will need to be stacked to reveal the galaxy's glory.  I will come back to this in coming weeks.

M88

A favorite spring galaxy that I imaged last year.

About 60, 21.2-second subs were stacked to create this image.

M88 is obvious in even one-second preview exposures and displays a lovely tilted-edge appearance, in which the face and compact spiral arms can clearly be seen.  SEDS.org notes:

I will return to this galaxy as soon as possible, hopefully to devote several hours of guided imaging to its disk.

M104

 

Who doesn't like the Sombrero Galaxy?  It stands out so distinctly in the eyepiece, and even in the DSI Pro's one-second preview exposures.  My session was coming to an end when I took this shot and the sky seemed to be growing a little hazy, a pinkish tint creeping across the dark firmament.

This image comprises 50, 21.2 second exposures and has been flipped upside down so that the galaxy appears “right side up.”  The central dust ring is very prominent in this image, leading one to believe that a longer exposure and better focus could produce a spectacular image.