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View Full Version : Object of the Week, May 29, 2022 – NGC 6070 & Friends



Paul Alsing
May 29th, 2022, 09:59 PM
Object of the Week, May 29, 2022 – NGC 6070 = UGC 10230 = PGC 57345 - SERPENS CAPUT

R.A.: 16h09m58.9s Dec.: +00°42'34" (2000)
Size: 3.2' x 1.7'
Magnitude: 12.40 B - Surface brightness 22.3 Mag/arcsec²

NGC 6070 is a gorgeous type C spiral galaxy in Serpens Caput, about 100 million light-years distant, presented to us about midway between face-on and edge-on. It was discovered by William Herschel on May 3, 1786.

While doing my Google due diligence about this object I learned a little trivia that I had not previously known, which is that back in 1998 NGC 6070 was the object chosen by the Sloan Digital Sky Survey for it first-light test sky images!

https://apod.nasa.gov/apod/ap980610.html

Also during my research I came across this paper…

https://arxiv.org/pdf/1004.4636.pdf

… which explores Giant HII Regions in this galaxy (and also in the wonderful NGC 7479). According to the photos in this paper, the 2 of the HII regions correspond to the 2 obviously blue star-like objects on the NE end of the galaxy! I’ll need to revisit this guy and see if they are visible in my 25” f5 Obsession tomorrow night… if the predicted wind fails to appear…

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This galaxy is almost exactly twice as long as it is wide, oriented NE-SW and has arms that disappear near the center on photos. This is a very photogenic galaxy! In the eyepiece I can see a fairly bright core and just a hint of an arm on the east side… but this was before I knew about the HII regions!

NGC 6070 has a couple of companions, those being NGC 6070B and NGC 6070C, both off the NE end of NGC 6070. Check out this labeled photo taken by the late Rick Johnson, which makes them easy to locate…

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NGC 6070B (CGCG 023-018) is actually a double object and is very faint. I saw some elongation here but no split was attained by me. NGC 6070C (PGC 1175364) is *really* faint and I only suspected that I saw it… and I’m sure you have all been there and done that :D

As always, give it a go and let us know.

Steve Gottlieb
May 29th, 2022, 11:12 PM
My experience with splitting the NGC 6070B pair was similar to Paul's -- probably to be expected as I was viewing in a similar-sized 24" scope. NGC 6070C was visible with averted, but called "extremely faint". I also logged the blue star-forming region at the NE tip of NGC 6070, but it appeared stellar or virtually stellar.

24" (6/28/14): fairly bright, large, elongated SW-NE, 2'x1', contains a large brighter core, fades out around the periphery. A very faint "star" seen near the northeast tip is actually a compact HII region labeled as region IV in the 2010 paper. Located 8' SE of mag 6.7 HD 145204.

NGC 6070 is the brightest in a trio with NGC 6070B = CGCG 023-018 (double) 4.2' NE and NGC 60670C = LEDA 1175364 5.6' NE. NGC 6070B appeared very faint, small, elongated 2:1 ~N-S, low surface brightness. This is a close double system and the noted elongation implies both systems were seen, but not individually resolved. NGC 6070C was extremely faint, very small, round, 12" diameter.

By the way, the fainter companions are much more distant at ~590 million l.y. (similar redshifts), compared to NGC 6070, which is ~100 million l.y. away.

As expected, NGC 6070B was a snap to resolve cleanly into its two components in Jimi's 48", even in poor seeing (the nuclei are separated by 16"). NGC 6070C was brighter than either component of NGC 6070B with a moderately high surface brightness.

obrazell
May 30th, 2022, 06:38 AM
Probably worth noting Paul also covered this object in 2019 https://www.deepskyforum.com/showthread.php?1289-Object-of-the-Week-June-30th-2019-NGC-6070-amp-Friends

Paul Alsing
May 30th, 2022, 01:43 PM
Probably worth noting Paul also covered this object in 2019 https://www.deepskyforum.com/showthread.php?1289-Object-of-the-Week-June-30th-2019-NGC-6070-amp-Friends

Whoa... I thought I had done a pretty good search to verify that my OOTW was new to the forum... but apparently not good enough!

Well, one of the good things about getting old that you get to hide your own Easter eggs and meet new friends every day!

Steve Gottlieb
May 30th, 2022, 10:00 PM
I'm not one to complain, Paul -- I posted on the first thread too!

Us old guys have to stick together :D

Uwe Glahn
June 1st, 2022, 06:14 PM
Paul, I can contribute one observation with the 27-inch. Seeing was above average. I uses 419x.

NGC 6070B was separated without any problems but both cores were visible in one larger halo. I noted NGC 6070C brighter than B. So C was nearly visible with direct vision, while B was only averted vision.

The brightest HII region ([ZBF2015] NGC 6070 1/3) to the NE was clearly visible as a nonstellar spot. The fainter HII region ([ZBF2015] NGC 6070 2) to the SE was only suspected.

The spiral structure was not clearly visible. Some dark lanes indicated the spiral.

sketch: 27", 419x, NELM 6m5+, Seeing II-III
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home (www.deepsky-visuell.de/Zeichnungen/NGC6070.htm)