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Object of the Week October 19, 2014 - Shakhbazian 317 Galaxy Chain
Shakhbazian 317
Galaxy Chain (6' length)
Cetus
RA: 02h 10m 41s
Dec: -06° 35' 12"
Magnitude: V ~ 14.5-16.5
If you enjoy galaxy chains or linear galaxy groups such as HCG 55, 56 and 27, Shakhbazian 16 and 166, Burbidge's Chain, etc., then check out Shakhbazian 317!
If you're not familiar with Shakhbazians, these are compact clusters of compact galaxies catalogued by Armenian astronomer Romela Shakhbazian. These groups are similar to several of the fainter Hicksons -- in fact, HCG 97 = Shkh 30 and HCG 50 = Shkh 5. The members, in general, are very compact, reddened ellipticals and some of the groups consist up to 15 members. It is not uncommon that some of the individual objects in the groups have turned out to be single stars.
Many of the Shakhbazians are extremely challenging targets with magnitudes from 14 down to 19 or 20. In fact, Shkh 1, discovered in 1957, was so distant (1.5 billion light years) and compact (1.2' diameter), that is was first thought to be a distant star cluster. I would consider it one of the ultimate deep sky challenges. During the 1970's, Shakhbazian and collaborators, found 376 additional compact clusters by examining a selection of 200 POSS plates and published the results in a series of papers.
For more on the Shakhbazians, including visual observations, check out Andreas Domenico's site.
Several of the galaxies in Shakhbazian 317 were first catalogued by Russian astronomer Boris Voronstov-Velyaminov in the MCG during the mid-1960's, so carry PGC designations. Officially, there are 7 Shkh 317 members that were catalogued by Romela. Here's the important data ...
Shkh 317-1 = MCG -01-06-064 = PGC 8340
02 10 53.4 -06 33 34
Size 0.5'x0.4'; PA = 145d
Mag 15.7B
Shkh 317-2 = PGC 96667
02 10 53.2 -06 34 54
Size 0.35'x0.3'; PA = 107d
Mag 16.7B
Shkh 317-3 = MCG -01-06-062 = PGC 8329
02 10 43.2 -06 34 47
Size 0.35'x0.3'
Mag 16.3B
Shkh 317-4 = MCG -01-06-061 = PGC 8330
02 10 40.9 -06 35 05
Size 0.4'x0.25'; PA = 36d
Shkh 317-5 = MCG -01-06-060 = PGC 8328
02 10 36.6 -06 36 01
Size 0.35'x0.15'; PA = 147d
Mag 16.7B
Shkh 317-6 = MCG -01-06-059 = PGC 8316
02 10 35.6 -06 36 23
Size 0.3'x0.2'; PA = 179d
Mag 16.9B
Shkh 317-7 = MCG -01-06-058 = PGC 8315
02 10 32.8 -06 36 59
Size 0.4'x0.4'
Mag 15.9B
With my 18-inch, I had no problem pulling in 5 of the galaxies in this 6' southwest to northeast chain from my local "blue/green" site (elevation 1200 ft). Shkh 317-7, at the southwest end, was the easiest in the chain and appeared faint, round, 15" diameter. A mag 12 star lies 2' south-southwest. About 3' northeast is the double system Shkh 317-3 and 317-4 (38" between centers). I logged Shkh 317-3 as very faint, round and slightly brighter (more condensed core) than Shkh 317-4. Sometimes this close pair merged into a single object. Another 3' east lies Shkh 317-2. It appeared very faint, round, 10" diameter A mag 12 star lies 1.9' NNW. Finally just 40" SE of the mag 12 star is Shkh 317-1, a very faint, extremely small glow, 10" diameter.
I've yet to look at this group with my 24-inch, but in Jimi's 48-inch, all 7 were easily resolved as well as a few additional fainter members such as 2MASX J02105688-0633464 and 2MASX J02110254-0632537. Extending the direction of the chain further to the northeast will eventually lead to the edge-on MCG -01-06-067 = FGC 258.
Attachment 1400
I'm guessing a 12-inch or 14-inch will show at least a few of the brighter members from an excellent site. Will a 16-inch or 18-inch show all 7 members?
“Give it a go and let us know”
