Compiled by:
Glenn Chaple
Introduction
Deer Lick Group – Galaxy Cluster near NGC 7331 in Pegasus
NGC 7331 (Magnitude 9.5, Size 10.5’ X 3.5’)
NGC 7335 (Magnitude 13.3, Size 1.2’ X 0.5’)
NGC 7336 (Magnitude 14.5, Size 0.8’ X 0.4’)
NGC 7337 (Magnitude 14.4, Size 1.0’ X 0.8’)
NGC 7340 (Magnitude 13.7, Size 0.9’ X 0.6’)
To capture this month’s Observer’s Challenge, we need to travel to the northwest corner of Pegasus and the galaxy NGC 7331. We might consider this spiral a “Messier Miss,” for it’s brighter (magnitude 9.5) than a number of galaxies the French comet hunter included in his Catalog of come-tary imposters. Credit for its discovery goes to William Herschel, who came upon it in1784.
The good news is that NGC 7331 is bright enough to be seen with the smallest of telescopes. The bad news is NGC 7331 isn’t our challenge. That comes instead from a quartet of small and faint galaxies located just to its east. The four, NGC 7335, NGC 7336, NGC 7337, and NGC 7340 are known collectively as the Deer Lick Group, nick-named in the 1980s by amateur astronomer Tom Lo-renzin who viewed them from the Deerlick Gap Overlook in the North Carolina mountains. Their small size (all have dimensions of around one arc-minute or less) may have been the inspiration for a second nick-name, the Fleas.
The Deer Lick Galaxy Group offers one challenge for the visual observer. Can you even see it? In his book Cosmic Challenge, author Philip Harrington considers it a test for medium-sized (6- to 9.25-inch) telescopes. In areas with even a slight amount of light pollution, you may need twice that aperture for even an averted vision glimpse. At visual magnitude 13.3, NGC 7335 is the brightest member of the group. It was discovered by Herschel a week after he found NGC 7331. The mid-13th magnitude NGC 7340 and the mid-14th magnitude NGC 7336 and NGC 7337 would remain unseen for 65 years until spotted by William Parsons, the 3rd Earl of Rosse, and his assistant George Stoney using the “leviathan” 72-inch reflecting telescope at Birr Castle.
Don’t despair if the Deer Lick Galaxy Group is beyond your telescopic reach. NGC 7331 is a worthy “consolation prize.” Located at 2000.0 coordinates RA 22h37m04.1s and DEC +34o24’56”, it’s about a 4 degree star-hop north and slightly west of the 3rd magnitude star Matar [eta (η) Pegasi]. This steeply inclined spiral is as large, if not slightly larger than our own Milky Way. Its appearance visu-ally and especially photographically earned it a place (number 30) on Sir Patrick Moore’s Caldwell Catalog.
The distance to NGC 7331 has been variously listed as around 40 to 50 million light-years. The Fleas have distances estimated at between 290 and 370 million light-years.
NGC 7331 and Deer Lick Galaxy Group Finder Chart A
(www.skyledge.net)
NGC 7331 and Deer Lick Galaxy Group Finder Chart B
(www.cloudynights.com, taken from Phil Harrington’s book Cosmic Challenge)
Reports
Mario Motta
NGC7331 is 40MLY away in pegasus, and comprises the main spiral and several small galaxies in one view. (these other galaxies are not related to 7331, they are a group about 350 MLY away). As Roger Ivester has pointed out, It is also known as the Deer Lick Group. In the 1980s, amateur astronomer Tom Lorenzin was observing in the mountains of North Carolina, at the Deerlick Gap Overlook. Because his view of NGC 7331 and its surrounding galaxies was so memorable, he christened them the Deer Lick Group. This image was taken with my 32 inch F6 telescope, with a ZWO 6200 camera and RGB filters. Processed in PixInsight.
Doug Paul
Canon 80D, 1200mm FL f/8.0 lens, ISO 800, 108 x 2min = 3.6hr total, 1/2 scale, north up
Venu Venugopal
Deer Lick group of galaxies. The galaxy lies at the distance of about 45 million LY, and is thought to be similar to the Milky Way in mass and diameter of 120,000 LY. The galaxy is reced-ing from us at 815 Km/sec. The galaxy is peculiar in that its central core is asymmetrical and rotates in the direction opposite to the spiral arms. This suggests an ancient collision or substan-tial gravitational interaction with another major galaxy.
NGC7331 is the brightest member of the “Deer Lick” galaxy group which also includes NGC7335, NGC7336, NGC7337, and NGC7340 lying at respective distances of 332, 365, 348 and 294 million LY. These distant galaxies appear to belong to a true galaxy cluster, but it is not certain if NGC7331 is actually involved, or merely lies in the foreground.
Image taken the with a SCT C11, about an hour of exposure with 10 second subframes (no guiding) on a GEM45. Processed in PI.
Doug Arion
Here's a shot of the group using a Mallincam DS10C on my homebuilt 10" f/4.5 reflector. Not the greatest -- but it's amazing what you can do with a video camera!
David Hinds
Here’s my image of Deer Lick Galaxy Group. It was taken with a Unistellar Equinox telescope during full moon lit sky from Tewksbury Ma. The green identifiers are post processing by As-trometry.net.
Russell Cox
Here's what a cheap telescope (Seestar S50) can capture of the Deer Lick Group from the bright lights in the City of Boston.
Dave Wilbur
This is my report for the November observer's challenge. Visually the bright core of NGC 7331 was easy to find with my 8in SCT with goto mount. There was no hope of visual confirmation of the dim companions. A 40 min exposure of NGC7331, with my Seestar S50 (50mm, f5) showed an unexpected surprise. Another galaxy group in the lower left of the image. I later determined this to be Stephans Quintet. Data collection was stopped because of clouds. I combined this im-age with data from two other nights, also limited by clouds. A zoomed in view of the area around NGC 7331 shows the 4 companions, annotated with NCG numbers directly to the right of each galaxy.
Justin Lutz
Celestron C8 with 0.63 reducer AM5 mount ASI1600mm with LRGB filters
Guiding with Celestron OAG and ASI174mm mini guide camera.
About 14 hours total exposure time (288 x 3 min subs) Processed in PixInsight.
Photo of Deer Lick Group taken by
