Object of the Week, June 5, 2022 - Arp 71, NGC 6045 in Hercules

[FaintFuzzies]

Object of the Week, June 5, 2022: Arp 71, NGC 6045 in Hercules

Type: Galaxy Pair
RA: 16h 05m 08s
Dec: +17 45’ 27”
Size: 1.3 x 0.3’
Mag: 14.9b

This week’s OOTW is a memory trip to my early observing days. When I was a kid, I enjoyed going to the library and checking out various astronomy books. In one of the picture books of galaxies, I saw a photo of a galaxy that looked odd, much like a golf club in a rich field of galaxies that stuck to me. At the time, I had no idea that it was a cluster of galaxies. I had only a 6” reflector at the time and had no hope of seeing it. About 5 years later, in 1980, I picked up an 8” reflector and hoped to see it. I failed after a few attempts. I was observing from my backyard, which wasn’t dark at all as I wasn’t old enough to drive.

During my early “serious” observing years with my 8” reflector, I picked up a series of observing books deemed as classics today. Among my favorites were Burnham’s, Webb Society Deep Sky Observer’s Handbook, Sky Altas 2000.0 and Vehrenberg’s Deep sky Splendors. I’m sure there are others, but those are my favorites. Oh, there is the AstroCards by Glen Sanner and George Kepple. Yes, I still have the hand drawn version! I'm mentioning all that is because I love going poring through the resources for observing targets. My Sky Atlas had about a dozen annotations from back then and this weeks OOTW was one of them. It was much fainter than the other added objects, but this is the impact NGC 6045 made on me when I was a young.

After grad school, I finally was able to afford a 16” reflector. I took it up to Blue Canyon one day and went for it. I was so happy to finally see it! I didn’t see the companion that formed the “club’ part. I saw it with a bunch of other galaxies in the field. It was way cool!

Under dark skies with my 22”, I took some time and had a pretty good observation. Here are my notes “NGC 6045 is a considerably faint, 4:1 elongated patch with an almost stellar nucleus. PA = 100 and about 60” long. Kicking it to 528x, the west end took a slight curve towards the north. The east tip took a 60 degree turn to the south and it is a little brighter than the halo, but fainter than the nucleus. The eastern tip is MAC 1605+1745."

This object isn’t the kind of challenge object that I normally post, but a fun object in a rich field of galaxies with a higher than usual percentage of spiral galaxies. Many Abell galaxy clusters tend to have more ellipticals than Abell 2151.

So give it a go... and let us know!

NGC 6045 SDSS.png
SDSS image

NGC 6045 30min.gif
30’ field centered on NGC 6045

Arp 71.gif
15’ labelled negative DSS field

Arp71-528x-68.jpg
22” at 528x Field: 6.8’
Seeing: 7/10 Transparency 7/10 NELM: 6.5



Anyhow, as always, give it a shot and let us know.

[akarsh]

Excellent choice of object. I like to call this one the "Hockey Stick of the Hercules Cluster", although it's not exactly like a hockey stick and more like a golf club as you described it. I haven't actually logged this object systematically, and incidentally, this was one of the things I wanted to do during GSSP this year.

However, I had a particularly memorable view of it one night on Jimi's 48", where it basically looked like a photograph. Hopefully, I can post a more detailed report after GSSP.

[Steve Gottlieb]

In my 24", I can only glimpse the companion as a tiny glow barely south of the east end of NGC 6045. Good conditions are required as the SDSS g and r magnitudes suggest V ? 16.8.

It wasn't exactly bright in Jimi's 48", but readily seen as a small thin glow, perhaps 12"x5"

[Uwe Glahn]

Impressive observation Alvin. You saw both, the slightly curved body of NGC 6045A and the elongation of NGC 6045B.

I personally missed the elongation of B by having soso seeing conditions and only normal transparency.

sketch: 27", 419x, NELM 6m5+, seeing III-IV
NGC6045-Gruppe.jpg
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