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Object of the Week, June 20, 2021 – Arp 302, VV 340, UGC 9618
Bootes
Galaxy pair interaction?
Magnitude (v): 15.3 and 15.7
RA: 14 56 54
Dec: +24 36 00
More popularly known as the Exclamation Mark Galaxy, I had this to say about the name when I observed this pair last summer with my 28-inch scope:
“The name is a bit confusing because the star between the two galaxies would seem to be the point of the exclamation mark. But it’s the two galaxies that inspire the name – an edge on and face on galaxy. Cool pair, 408x and 547x, 21.75 SQM.”
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Wikipedia indicates this pair has a light travel time of 470 million years, and seem rather bright for being that far away. Each galaxy is approximately mid-15th magnitude, but together they seem brighter. That’s good news for us, because they’re a pretty sight in the eyepiece.
The z of each galaxy doesn’t match up very well though. VV 340A - the edge on galaxy – translates to a light travel time of 246 million years, while the edge on galaxy, VV340B, seems a bit closer to the advertised light travel time with a z that works out to 450 million years. So perhaps these two galaxies are a line of sight coincidence.
The seeing was mush during my observation, and I’m hopeful to give it another shot this summer under sharper seeing conditions and try to detect the dark lane of VV 340A and perhaps a spiral arm or two in VV 340B - but I’ll probably be pushing my luck on both counts. I definitely won’t see them unless I try, so the effort will be worth it regardless of the outcome.
The background galaxies that appear so vividly in the HST image are all fainter than magnitude 18.3, so there’s an outside chance I might see the brightest one, but that’s the best I can hope for with my scope. How about you?
Give it a go and let us know!
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