clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.

Wednesday, March 28, 2012

Polar Alignment & M-101

On 3/26, I had the scope out on what appeared to be a pretty transparent sky.  I have been having trouble polar aligning in the past, and on a whim, I did a google search on polar aligning the CG5.  The manual says there is a polar align function in the utilities menu, but there is none in my menu.  I did find a short mention on it in a forum online.

I went out, did a 2-star alignment, added 2 calibration stars, then when I was finished, I hit the align function.  There it was, a polar align routine that calculated the polar alignment on the last star I was at.  The scope skewed to where the scope calculated that the star should be, I adjusted the azimuth and elevation to center the star.

Let me say that the alignment was absolutely perfect.  I snapped off an image of M51.  A single 3-minute frame and it looked like this...

This is a lightly processed, 3 minute exposure- single frame, and is better than anything I've taken of this galaxy to date.  I didnt do anything any different except the alignment.  The focus might be better than before but I really cant explain why this 3 minute exposure turned out better than 1 hour exposures I've done in the past.  This is a cropped 3 minute iso 800 exposure thru the C6.

After seeing that, I thought I'd photograph another object... but what should I photograph?

Well, I have never photographed M101 before, so that was the target.  I skewed to M101, and without taking the camera off of the scope, I snapped an image.  M101 was centered perfectly in the frame, so I shot 15 or so frames.  In the past, I was going to shoot M101, but it was so dim, that I turned to another object.  This night, M101 was plainly visible in a 3 minute sub.  I did not try any 5 minute subs during this session, as I was not autoguiding.  I actually didnt think that the 3 min subs would be that good with no autoguiding, but... the 15 stack image came out fantastic.  Here it is:

This is an image where I used no calibration frames whatsoever...  no darks, no flats.  I did crop the image because there was a pretty nasty gradient.

Remembering that there is a supernova in this galaxy, I did an online lookup, looking for the SN and I did find it in my image in this picture....

I did not try to calculate the magnitude, but if I recall, its dimmer than mag 17, and I cant approximate lower than 17.

Notice how round the stars are.  None of these images are guided - this is just the bare mount, and so far have been my best images, guided or not.


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