Object of the week May 19, 2013 - Arp 97

Arp 97, MGC+5-29-10/-11/-12
Ursa Major
RA: 12 05 47.8
Dec: +31 03 39
Size: 2.4 x 1.4’ (determined by megastar and encompassing the three galaxies)
Mag: MCG+5-29-10 (15.7), -11 (15.3), -12 (15.5)
Urano: 54L

In actuality, Arp 97 consists of just the two interacting galaxies (-10 and -11) while the nearby -12 is just in the right place where if you took the image and rotated it counterclockwise 120 degrees, you get a “coat hanger”. That is how it appeared in Jimi’s 48” scope. Pretty cool object. The redshifts of the three galaxies suggests that they are approximately the same distance from us. -10 and -11 is about 318 mly, while -12 is 340 mly distant.

Below are my two observations of this object:
48” (488x) (NELM 7.5) - Very cool coat hanger looking group of galaxies. The hook off MCG+5-29-11 is considerably faint, but obvious. It hooks to the west side hooking to the south. It is brighter than the connecting streamer to MCG +5-29-10, which lies 2.4’ due north. The two mentioned galaxies group forms a coat hanger with MCG+5-29-12, despite that there are no bridges to MCG+5-29-12. Very cool object in the 48”

22" (255, 305, 377 and 458x) (NELM 6.5)
MCG+5-29-11 appeared as a 3:2 elongated even surface brightness patch with no central brightening.
PA = 20º and 15” long. The “hook” was not detected. Its companion, MCG+5-29-10, lies 1.2’ north and is a faint round even surface brightness patch. No faint extension detected. Probably need a better night and a larger scope. 10” across. MCG+5-29-12 is a very faint round even surface brightness patch. Lies 1.3 SE from -11. Note: This observation was done more than 10 years ago with “high-glass” eyepieces. This object deserves a re-observation with the same scope, but with my ZAO-II eyepieces.

SDSS image
Attachment 664


Sketch with my 22”

Attachment 665
22” f/4.1 reflector @ 377x Field: 10.3’
Seeing: 7/10 Transparency: 7/10 NELM: 6.5

So….

“GIVE IT A GO AND LET US KNOW”
GOOD LUCK AND GREAT VIEWING!

Alvin last year when you and I looked at Arp 97 I was stunned by the appearance of the coat hanger look of the three galaxy's. This will be on my top 10 list of galaxy groups now. This is a cool looking object!

Alvin...

You referred to "high-glass eyepieces".

What do you mean by that?

Alvin, I happened to literally stumble across Arp 97 two weeks ago, when my intended object was KTG 41 = Rose 8, an easier triplet just 15' NW of Arp 97! When I moved to the field, though, I first noticed a pair of very faint, very small glows (cores of the main galaxies in Arp 96), but wasn't sure what objects they were. After identifying the KTG 41 triplet which was outside the eyepiece field, I realized the initial pair I spotted was Arp 97 and took a second look. I didn't notice the "hook" or connecting bridge with my 24-inch.

Also, Arp 97 reminds me in structure to Arp 238, another pretty remarkable target.
Attachment 671

Lou wrote:

You referred to "high-glass eyepieces".

What do you mean by that?

LOL High glass count eyepieces, such as Naglers, Ethos, etc. I'm pretty sure that I used a combination of Naglers and Radians with an XW thrown in there while observing that group back then.


Steve, thanks for your note regarding the hook or bridge. But your conditions last week was not very transparent, maybe you might see it under more transparent skies.

Okay... Makes sense.

I have a thought, but to avoid hijacking this thread will take it elsewhere.

Thanks...

Steve: it is interesting that Arp97 forms a chevron of very similar dimension and orientation to the treo with UGC7064 you were seeking. That may have been a puzzler! This double-treo seems like it may be a curious thing to seek out with PGC38307 completing the 'treo' near Arp97

Alvin,

last nights I tried the hook and the bridge with my 27". Under good conditions NELM 6m5+ and 419x I could see the hook as a faint glow separated from the core. The bridge to the separated detail and the bridge between both MCG's was not visible.