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Galaxy hunting


themos

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Four of us met at Britwell Hill on the 22nd of April, just after sunset. High cloud had mostly dispersed leaving clear but a bit hazy skies, apart from a 15-degree band near the horizon. This was just enough to obscure Mercury, although we were convinced for a while that Aldebaran was it!

We set up at the top of the hill, next to some trees to the west: my 12" SkyWatcher Dobsonian, a 10" Orion Newtonian Dobsonian and a 10" Orion Optics Newtonian on a Meade LXD75 Goto GEM. We also had some 10x50 and 15x70 binoculars and a tripod mounted Canon DSLR. I also brought along my wooden stabilising frame for binoculars.

The theme for the night was galaxies. After some cooling time and rough collimation we started on the Leo galaxies (after the obligatory glimpse of Saturn). First was the Leo triplet group M65/M66/NGC3628. The jumping off point for this is the bright (mag 3) star Chertan (Theta Leonis, 70 Leo), in the belly of the "lion", towards the rear. Sweep down from the lion, about 2.2 degrees to get to the mag 5 star 73 Leo, a spectroscopic binary. From there, 1 degree left brings you to center of the Triplet, with M65/M66 below and NGC3628 (discovered by Herschel) above. The brighter Messier pair was easily visible in all the Newtonians, showing the elongated shape of each one.

Next up, the other Leo group M95/M96/M105. That's trickier to find but the mag 5 star Kappa Leonis (between Chertan and Regulus, aka 52 Leo) is a good jumping off point. The galaxies are about 2 degrees down from it. As it happened, I got lucky and they quickly popped up in the eyepiece as I was trying to find Kappa in the finderscope. Again, elongated shapes were nicely visible in the 12mm Nagler at 125x.

We then left Leo to look for galaxies in Coma Berenices and the first target was M64, the Black-Eye galaxy. Now, to find this, you go to the "cup" of the Coma, the Melotte111 asterism, where 13 Com and 12 Com define the bottom of the cup. Then 2.5 degrees south east of that is an asterism trying to form a circle (18, 21 and 22 Com are there). Another 2.6 degrees in the same direction takes you to a "peace sign" asterism, one star in the middle and 3 arranged uniformly around it (23, 26 and 20 Com are the "perimeter"). Lastly, 4.25 degrees to the east of that is a lone star (35 Com) and M64 is just to the northeast of that, about a degree away. I know this now because I thought I had found it but in my eyepiece view there was a bright star next to it and the others did not see anything like it. So what was I looking at? NGC4494 fit the description and it was 7 degrees away, just east of the cup. Never mind, bagged another one! Eventually, by memorising the star hopping procedure I just described, the Black Eye galaxy popped up. And yes, you could tell there was something dark smudged across its bottom bit (the north side in the eyepiece).

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