Three Images from Friday Night

March 26, 2011

Dick Steinberg

The second of two consecutive nights of clear skies! Hyperion images from the Blue Mountain Vista Observatory. North is up and west is right in all images. For full detail, magnify the images.

NGC3718 (also known as Arp 214), a fascinating magnitude 10.6 severely deformed spiral galaxy in Ursa Major. Eighty minute exposure. Interaction with NGC3729 (the ring galaxy 12 arc-min to the east) is the likely cause of the extreme deformation of both galaxies. Note the helical shape of what formerly was NGC3718's equatorial dust band. A measured radial velocity of 994 km/sec would place it at a distance of roughly 46 Mlt-yr (million light years).

M109,  magnificent magnitude 9.8 barred spiral galaxy 40 arc-min SE of Phecda (Gamma Ursae Majoris). 60 minute exposure. Its 1048 km/sec radial velocity (if entirely cosmological) would place it a distance of about 48 Mlt-yr.

Coddington's nebula (IC2574) , a dwarf spiral and member of the relatively nearby M81 group in Ursa Major, located three degrees east of M81. Listed at magnitude 10.2, but extremely faint due to its large extent (13.2 x 5.4 min). At least two hours of exposure would be required for a good image, compared to the 30 minutes available last night. Coddington was a late19th/early20th century American astronomer who discovered this obscure galaxy. An interesting VLA radio image appears here. My impression is that this object is still in its formative stages. Perhaps its dark matter clump and central black hole are not massive enough to allow normal galactic evolution.

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Hyperion 317mm f/8 corrected Cassegrain - Paramount ME - Apogee U16M - 4096x4096 nine-micron pixels binned 2x2 - 0.73 arc-sec/unbinned pixel - uncropped field-of-view 50 arc-min square - image acquisition and processing with MaxIm DL 5.14 - calibration (sky-flat/dark/bias) - system automation: CCD Commander 1.6.33 - piggy-back guider Orion 80mm f/11.4 + SBIG ST8 camera - 5-minute subexposures -  Blue Mountain Vista Observatory.