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View Full Version : Object of the Week, November 9th, 2020 – NGC 7609



FaintFuzzies
November 8th, 2020, 05:43 PM
Object of the Week, November 9th, 2020 – NGC 7609, HGC 95 and Arp 150
RA: 23 19 30 Dec: +09 30 28
Size: 0.8 x 0.5’ Mag: 14.9b

The Object of the week is NGC 7609, which is the brightest member of Hickson Galaxy Group 95 (HGC 95) and also known as Arp 150. In the Arp catalogue, Arp 149 to 152 contains some sort of jet and NGC 7609 has a jet that appears to be shooting out to the SE of the core. But upon closer examination of the SDSS image, it seems to be part of the galaxy to the SE and not NGC 7609 and it looks like an interesting group of multiple interacting galaxies. Here is an article that talks about a 3-galaxy merger, which NGC 7609 is involved in. https://iopscience.iop.org/article/10.1086/310953/fulltext/975342.text.html

Through the eyepiece, I’ve observed it several times and the notes are as follows. Note: I have not attempted this object with anything larger than a 22” reflector. I will try with a larger scope in the future.

22” f/4 reflector @ 203, 377, 528 and 881x
At 377 and 528x, Hickson 95 contains one dominant member (NGC 7609, component A) with only one visible member MGC+1-59-48, component B). Bumping up the magnification to 881x, a third member (MCG+1-59-46, component D) popped in and out. The group fits in a 1.5’ circle.
Component A – Considerably bright round patch with a brighter core. Averted vision shows only a little more. I didn’t see the jet.
Component B – 3:1 elongated faint even surface brightness patch. About 30x10” and PA = 135. About 45” SE from NGC 7609.
Component D – Extremely faint and slightly elongated. Even surface brightness patch. 10” long and PA = 0. About 1’ SW of NGC 7609.
Component C – not seen

Steve Gottlieb have seen this object couple times through Jimi’s 48” scope.

I just thought that this object is well placed high in the sky at this time of the year. When you look at it and even if you see just NGC 7609 as a faint round glow, just think what is really going on there. Since I was a kid, I always imagined the richness of deep sky observing if we were in a galaxy involved in a collision or a merger. If we were in component C, the spiral galaxy, there would be all sorts of cool stuff to look at. Also imagine that the “Milky Way” isn’t just a straight line, but multiple lines criss-crossing the sky with this huge glow, which would be NGC 7609!


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Figure 1: Image from the Sloan Digital Sky Survey


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Figure 2: Labelled DSS image


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Figure 3: Eyepiece rendition at 528x


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

Ivan Maly
November 9th, 2020, 12:12 AM
This is a nice write-up, Alvin, and one of my favorite objects. This is what I have from three years ago, on a solid good SQM 21.3 night with our club's observatory 20-inch (F/5): "Arp 150, Hickson 95, Peg. W of m12 *, 2 m11 ** farther NE. Two faint stars on S edge of group. NGC 7609 (A) on N side is the most prominent, connected from E end to compact PGC 71077 (C) to SE. B and D differently oriented spindles on E and W side of the group in 13 mm. Examined also in 8 [mm]." Apparently, I saw the core of component C and its N arm, thinking the latter was some kind of tidal bridge or extension of the main galaxy.

Uwe Glahn
November 15th, 2020, 08:29 PM
Sweet galaxy group. I've logged two observations with two different apertures. In a rough translation from my Hickson-project (http://www.deepsky-visuell.de/Projekte/HCG_Start.htm) I wrote:
16", 360x, NELM 6m5+
difficult group; a visible as an easy elongated glow; c not separated from a; bridge not visible; b faint 1:3 glow with averted vision; d not visible

27", 586x, fst 6m5+
spectacular with larger aperture; a + c one complex with a as a round, laminar and concentrated glow; at the E end a 0,5' long bridge started towards the SE with a knot at its end (=component c); b as an elongated glow with another spot NW of the nuc; d as a 4:1 spindle even with direct vision
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home (http://www.deepsky-visuell.de/Zeichnungen/HCG95.htm)

akarsh
November 20th, 2020, 10:01 AM
I have an old log from 2013 August that is relatively sparse in information:

18" f/4.5 2013-08-03; near Pontotoc, TX

HCG 95:
05:02 AM -- Could hold the brightest part (one of the interacting galaxies) all the time. Sometimes, could "sense" its curvedness. Could hold the second brightest part (brighter of the two edge-ons)
occasionally in the 7mm Nagler (~300x). 4.5mm (~450x) proved to be too much power.
Astronomical Twilight is about to begin. The bright light seems to be moonrise.


It appears that I did not see the core 'c', the jet or the fainter edge-on 'd'. At this time, my mirror had a fairly damaged coating and I also did not have tracking, so I wasn't really seeing as deep as I should have with an 18". 'c' does look within the reach of an 18" under great skies, so I'll have to put this object for a repeat on my list :-)

I'm waiting for Steve Gottlieb to tell us what the view was like through Jimi's 48"!

Clear Skies
Akarsh