Object of the Week, September 3, 2023 - NGC 128 Group

[Steve Gottlieb]

Name: NGC 128 Group = LGG 6 (main galaxy data)
R.A.: 00h 29m 15.1s
Dec.: +02° 51' 51" (2000)
Con: Andromeda
Type: SB0 peculiar
Size: 2.5'x0.7' PA: 1°
Magnitudes: 11.8V, 12.8B

Akarsh Simha mentioned the NGC 128 group in a post back on Dec. 14, 2015, but it's never been an OOTW and it's certainly worth another look. The central compact group consists of 5 galaxies -- NGC 125, 126, 127, 128 and 130. A larger group (LGG 6) based on recessional velocities consists of the last 4 NGCs, as well as UGCs 275, 277, 281, 282, 283 and probably IC 17. These lie at a rough distance of 180 million l.y. (depending on your choice of Hubble constant). NGC 125 has a larger recessional velocity and may lay in the background.

NGC 128 Group.jpeg

William Herschel discovered NGC 128 (as well as NGC 125) on December 25, 1790 (sweep 985). He described it as "pretty bright, very small, round, very gradually much brighter in the middle, pretty well defined on the margin. The most detailed historical observation was made by J.L.E. Dreyer, while an assistant on the 72-inch at Birr Castle for the 4th Earl of Rosse (Lawrence Parsons): "Considerably elongated in PA 2.4°, much brighter in the middle, probably sharp on the following [east] side, and a little curved, convex side following."

Both William and John Herschel missed NGC 126, 127 and 130, but they were found in November 1850 when the 3rd Earl of Rosse (William Parsons) and his observing assistant Bindon Blood Stoney took a look. Here's the sketch made with the 72-inch, which perfectly matches the quintet.

NGC 128 group 72%22.jpg

NGC 128 has an unusual box-shaped center with sharper edges forming more of an "X" shape. The north-south spine of NGC 128 is clearly warped and it's apparently interacting with NGC 127 -- possibly the cause of the unusual core of NGC 128.

NGC 128 close-up.jpeg

NGC 125 is another odd galaxy, the result of a past interaction. Besides an off-center core, curved tidal tails to the east and west nearly form a nearly complete off-center loop to the north! This deep image is from the Legacy Survey. Click for higher resolution.

NGC 125.jpg

NGC 128 is faint but easily visible in an 8-inch (or smaller) scope. In fact, I first observed it over 40 years ago (Aug. 1982) in a C-8 and others in the group the following year with a 13.1-inch Odyssey I. Along with its two close tiny companions, the NGC 128 trio was striking in my 18-inch. My last observation of the larger group was a couple of years ago when I logged IC 17 and UGC 275 in my 24-inch. Both of these galaxies lie over the border into Cetus, but less than 30' southwest of NGC 128.

As always,

"Give it a go and let us know!
Good luck and great viewing!"

[Raul Leon]

Hi, here's my observation from 11/16/2017 : I used a 4mm Radian at 436x with my 14.5 StarStructure f/4.3Scan0641.jpg

[lamperti]

I saw 4 of these back in 2003 (on my birthday!) with a 20" at 282x:
NGC-128 - Fairly bright and oval in shape.
NGC-127 - Part of Trio #2; Can see some shape; next to NGC-128. Averted vision scale #3.
NGC-130 - Part of Trio #2; Just about at direct vision at 14.4 magnitude.
NGC-125 - Part of Trio #2; Round with brighter center; near a double star.

Back in 1991, with a 13" at 130x:
NGC-128 - Seen with NGC-125. Easier of the two. Ovalish with even brightness.
NGC-125 - Seen with NGC-128. Averted vision showed a round smudge.

[KidOrion]

10/1-10/2/22
LINSLAW POINT
SUNSET: 6:53 PM
MOON: 7 days (set at 10:23 PM; 41% illuminated)
SEEING: 6, 7
TRANSPARENCY: 5, 6
SQM: 21.4
NELM: not checked
WEATHER CONDITIONS: temps to 58F; slight dew later; air still and hazy; mild but clammy
OTHERS PRESENT: DB
All observations: 20? f/5 Obsession Dob, 14mm ES 82? eyepiece (181x, 0.45? TFOV) or 7mm TeleVue Nagler (363x, 0.21? TFOV) unless otherwise noted


12:38
NGCs 128, 130, 127, 126, 125 (Psc): If you keep looking for more-obscure stuff, your patience is eventually rewarded with something that’s impressive: this is the NGC 128 group in Pisces, and there are at least five galaxies here that are fairly easy to pick up. NGC 128 is a bright, well defined, somewhat-irregular galaxy that’s 2’ long, with tapering, fading arms; it’s oriented in 180? PA, due N-S, with a substellar nucleus; it’s 2.0’ x 0.3’, the core making up the middle 0.75’ of the galaxy (I know it’s got that irregular, box-shaped core, but at 181x I don’t really get a good sense of this). NF NGC 128 by 1’ is a tiny fuzzy spot [NGC 130] with what looks like a stellar nucleus to it; 0.75’ NP 128 is another small round galaxy [NGC 127] that’s much more diffuse, with no central concentration to it; it’s fainter than the one NF; neither is more than 0.25’ around, but both are pretty well defined. 4.75’ S slightly F NGC 128 is a 12.5-magnitude star; there’s a 12th-magnitude star SP 128 by 3.25’, and then from that star 1.67’ S somewhat F is another galaxy [NGC 126]: this one is oriented in 120? PA, so N somewhat P-S somewhat F, and spans 0.5’ x 0.3’; it’s diffuse and poorly defined and has a very small, gradually-brighter core that’s only slightly brighter than the halo; it also has 1’ SF it a 15.5-magnitude star, which is a distraction from the galaxy. 7’ P very slightly S of NCC 128 is a fourth galaxy [NGC 125], which at first seemed to have some N-S elongation, but now seems to be more just roundish; it’s the second-brightest in this group and is 0.67’ in diameter, with a sudden, brighter core, a substellar nucleus, and a reasonably well-defined halo; S very slightly P it by 0.75’ is the more-N of a pair of 12.5-magnitude stars; these are separated by 0.3’, with the S one S slightly F the more-N one. Speaking of bright… there’s NGC 128 in the 7mm, which I think is actually too much power, because the little “ears” are really hard to see now; the other galaxies are much better, but those two are not looking so hot. Switching to the 10mm Delos… wow, the Delos really brightens things up! (I can’t get over how much better this eyepiece is than all of my other ones.) [NGC 125] really is quite a fine object; it’s got a really striking nucleus. [NGC 126] is really quite well defined here, in opposition to my previous comments. The two “ears” of 128 are not particularly easy at this magnification, but they are still noteworthy, especially in averted vision. An excellent group!

[Clear Skies]

My log tells me I observed these five galaxies (in Pisces) almost 6 years ago under the skies of the French Ardennes. 14" SCT @ 168x / 29':

NGC125, that is component C of the double star HJ623 (WDS00288+0251):

A round glow, suddenly brighter in the middle. The nucleus is visible with AV.

For the double star: Two mag. 11.5 stars aligned almost due south (A) to north (B), the galaxy to the NNE thereof is component C of the double. ABC split.

Vorontsov-Vel'yaminov 894 = NGC127, NGC128 & NGC130

Without use of AV only the central galaxy NGC128 is visible, a slightly north-south elongated streak, brighter in a core that is slightly elongated in the same direction. With AV clearly more elongated, as is the core.
Using AV NGC127 is faintly visible to the WNW, to the east is NGC130: both are faint round patches, NGC130 is just a bit brighter than NGC127 is.

NGC126

Sharing the FoV with NGC127, NGC128 and NGC130 (Vorontsov-Vel'yaminov 894) to the NNE and with NGC125 to the WNW: A small, faint, slightly east-west elongated patch, even in brightness, with AV subtly brighter in the middle.

NGC125, NGC126, Vorontsov-Vel'yaminov 894_1.jpg NGC125, NGC126, Vorontsov-Vel'yaminov 894_2.jpg NGC125, NGC126, Vorontsov-Vel'yaminov 894_3.jpg

Click here to download to guide.

[Steve Gottlieb]

I was surprised to learn that NGC 125 is the C component of the double star HJ 623 (just off the southwest side in the photo of NGC 125). But checking the WDS notes, I see there are quite a number of similar cases. In fact, all members of the HCG 16 quartet are components of HJ 2116.

[Uwe Glahn]

Indeed a beautiful group. I noticed that I never visited with the 27", but only with the 16".

sketch: 16", 360x-600x, Seeing III, NELM 6m5+
NGC128-Gruppe.jpg
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