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Imaging at Holmbury - 7 May 2008

Sent in by Julia G.

On the night of 7th-8th May, Julia, Tony Q., Pam and Dick ventured up to the Holbury observatory to try out their newly acquired imaging skills. The target for the night was M64, the Black Eye Galaxy in Coma Berenices, also known as the Sleeping Beauty galaxy. A bit of a challenge maybe for a group of beginners, as it's small (10.0' x 5.4') and its apparent magnitude is only 9.4, but it is beautifully distinctive with a band of dark dust lanes obscuring the galaxy's bright nucleus.

First things first. We followed the dome procedures from the training sessions and set about performing a two star alignment. Soon of course the inevitable happened, and we got completely sidetracked while admiring our alignment stars. The seeing was poor, at best about 3 out of 5, but oh boy ! did that make the star twinkle. For those of us not used to the light-gathering power of a 20.5" scope, it was a stunning sight just to watch Regulus and Arcturus flashing and flickering in silver and gold. And while Leo was so well placed, we couldn't resist slewing to the Leo triplet and spending an indulgent few minutes studying this trio of galaxies. The spiral structures of M65 and M66 were clearly evident, with NGC 3628 rather fainter. The three together are said to give the impression of two eyes and a mouth, and we just managed to fit all three into the field of view to get (with a bit of imagination) a nice smiley face.

It was close to midnight by the time we fired up the CCD. Again, everything went smoothly apart from a little fiddling about trying to find an optimal focus. A fuzzy blob appeared on the screen. Knowing we wouldn't achieve much with the seeing so poor, we opted for just 15 subexposures of 15 seconds. The fuzzy blob persisted. Maxim's automatic align and combine functions refused to co-operate, probably due to the lack of bright stars to align on, so we packed up at that point, pleased we had at least saved some images.

The next day, Julia loaded up the images into Maxim once again, and persuaded it to perform an align using the 2-star method. Suddenly, the "wow!" moment ocurred. M64 did indeed emerge from the digital mist, with its unmistakable dark feature that suggests dust lanes. Just a little more processing in Photoshops was necessary to crop the image, adjust levels and apply a despeckle filter.

Of course, our image is poor compared to some of the ones we've seen from the training. However, as Pam says, it's much more interesting when it's your own. So we're pretty pleased with our first attempt, and can't wait to try again. It shows just what can be accomplished by a group of beginners given poor skies, terrible focus, and exposures that were too few and too short.

The ease with which we're acquired our first image has inspired us to try again soon, and we hope everyone who has done the training will follow suit.

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