Any observations of ESO 566-7, a very "serpentine" galaxy in Hydra?

[ScottH]

So, in my never-ending search for extragalactic H-II/star-forming regions, I stumbled upon the galaxy ESO 566-7 in southern Hydra. In images, it is an awesome looking galaxy that is now on my list to observe next time I get to use my friend's 36-inch dobsonian. I say that because while I'm sure I'll be able to see the core of each galaxy with my 16-inch, it is the thought of seeing those gorgeous, opposing spiral arms that makes my mouth water!

Scott H.

ESO 556-7 10arc.gif Screenshot 2022-12-24 11.18.50 AM.png
10'-wide DSS red image / Legacy Survey

[Steve Gottlieb]

This interacting pair is also Arp 252 and it reminds me of Arp 238. Quite striking!

Bill Keel has an old page here and this 1999 Multi-Color photometric study gives V magnitudes (at 26.0 mag/sq. arcsec) for the two galaxies, as well as the "plume", "bridge" and "tail".

[ScottH]

ESO 566-7/566-8 = Arp 252. Thanks for telling me that, Steve, because SIMBAD didn't!

Galaxy A = 15.60
Galaxy B = 16.16
Plume = 17.42
Bridge = 17.43
Tail = 16.68

But which part is the plume and the tail, I don't know!

Scott H.

[Steve Gottlieb]

Here are Alvin Huey's observing notes using his 22" f/4.1 @305, 377, 458 and 575x.

ESO 566-007 - faint 3:1 even surface brightness streak. No sign of a nucleus. PA = 70° and about 20" long. No spiral arms were seen with any magnification.

ESO 566-008 - faint 2:1 elongated patch with a brighter center. PA = 120° and about 20" long. It sits about 50" north. No spiral structure detected in either galaxy.

Steve

[ScottH]

Well, as I figured, the only hope I have to see it's delicate arms is with my friend's 36-inch, then. Good to know.

Scott H.

[Uwe Glahn]

These spirals are hard to detect Scott. I found an entry with a 28-inch under the best skies I had in my life (Gamsberg/Namibia, NELM 7m5+, Bortle 1).
I wrote (28", 450x, NELM 7m5+): both galaxies relative faint but steadily visible with direct vision, northern galaxy brighter; both arms only indicated and not clearly visible, best arm winding from the southern galaxy in a thin half circle to the south