Author Topic: galaxies galore  (Read 657 times)

mccarthymark

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galaxies galore
« on: January 04, 2017, 12:40:08 PM »
I had the good fortune to get out observing the night of 12/28-29.  I reported on some of my experience here http://www.deepskyforum.com/showthread.php?958-Snow-Galaxy-Clusters&p=5496#post5496.  But I wanted to share some other remarkable observations:

WLM (UGCA 444) & WLM 1: Wolf-Lundmark-Melotte is an irregular dwarf galaxy in the Local Group but far enough away from the others to not feel the exertion of the Group’s gravitational forces. Since it has not been jostled so much, forcing new star birth, it is thought most of its star formation occurred 13 billion years ago. It appeared as a large, ill-defined, low surface brightness oblong glow orientated N-S. There are several faint stars superimposed on the galaxy and around its halo. One of these is actually a globular cluster in the dwarf’s pull, WLM1. Using a finder chart to identify the correct point of light, it popped in and out with averted vision and seeing conditions, I could only hold it a moment or two; at 533x it was non-stellar. According to studies, the metallicity of the globular indicates its age is 15 billion years – which is amazing, if difficult, to comprehend.

NGC 1128-1 & -2: Overlapping halos, very close small round glows, each with bright cores, very small and faint. These are a pair of galaxies and are part of AGC 400. There were two other very small, extremely faint round patches glimpsed with averted vision in the field: to the SW (2MASX J02573365+0558371 15.1B) and to the south (MCG+01-08-028 15.7B). I suspected another one to the NE but not sure. Someday, I need to go into the AGCs better prepared, with finders, and really spend more time tracking components down.

NGC 1218: Fairly faint, round, stellar nucleus and diffuse edge halo. Halo mottled to south and north – could be a spiral? [It is an S0a Seyfert I – 397 mly away!]

IC 302: Fairly faint, fairly large diffuse glow, halo is round and mottled, with a bright small core, 3:1 N-S. Star just off southern tip of halo. [DSS shows a lovely face on spiral, 13.81B, SBc, 2.6:1.1]

IC 315: Very small, very faint, low / even surface brightness glow, brightens overall with averted vision; very slightly elongated NE-SW. Finely split, equal magnitude double star to the NW.

IC 1918: Small, very faint elliptical glow, even brightness, very slightly elongated NW-SE. Near an asterism of six stars shaped like a kite to the west. 427 mly distant – quite far! It must be very intrinsically bright.

I had a look at galaxies in Orion. Naturally most of us view Orion’s nebulae, but I thought I would spend some time with the galaxies to make them less lonely. I took a quick look at M42 then swung slightly west:

NGC 1924: Bright, pretty large, oval NW-SE, slightly mottled – must be a spiral. UHC seemed to lighten up a knot in the northern rim of the halo. Brighter, small core. [It is a lovely face on SBbc spiral, 1.6’x1.2’, 12.5V]

IC 421: Fairly faint, pretty large diffuse glow, mostly even surface brightness. It’s another impressive face on spiral in DSS.

MCG-1-14-12: Very faint, small, round, diffuse glow. Inside a triangle of similar magnitude stars. Another face on spiral, this one with disrupted arms.

UGCA 102 = Mrk 1094: Very small oval, gradually brighter to middle, pretty faint. It’s a blue compact galaxy, which [cribbed from Wikipedia] are often low mass, low metallicity, dust-free objects. Because they are dust-free and contain a large number of hot, young stars, they are often blue in optical and ultraviolet colors – and indeed the DSS image shows a bluish galaxy. They are not necessarily young galaxies; they might have been “well mixed” and thus efficiently used up its dust during its initial star forming period. Many show signs of recent interactions with other galaxies, and in DSS UGCA 102 does show some warping (its morphological classification is not straightforward: SABcd).

HGC 31: Hickson galaxy cluster. Component a/c was seen as a single irregular glow, not split. Component b was clearly seen, though small, very faint, slightly elongated. Component d, 18th magnitude, was not seen.

UGC 3271 = Mrk 1095: Very faint, very diffuse small 3:2 NNE-SSW glow with a small but bright quasi-stellar nucleus. A line of stars runs out from each tip in line with the major axis. It is a Seyfert 1 galaxy, which have quasar-like nuclei—which can be as bright as all the light output from a galaxy like the Milky Way. 444 million light years distant! And such a bright nucleus!

UGC 3258: Small, fairly faint, 3:2 N-S, quasi-stellar nucleus with star on northern tip. SBbc 12.9v. DSS image shows this as almost a ring galaxy, with perhaps a very bright knot on the northern rim?

CGCG-395-16: Lozenge shape 3:2 glow, gradually brighter to middle. I guessed a star was superimposed on the east rim but find in the DSS image it looks like a very bright knot running along this edge. It lies in a triangle of bright stars, one of which is STF 654. This needed to be out of the view for me to pick up the galaxy, but once seen I could hold the galaxy with the 4.62 magnitude STF 654A in view; the double is well split, yellow and yellow orange 8.5 magnitude B, 7”.

IC 413 & 412: at 333x, IC 413 is fairly faint, small, has a bright core & very faint but clearly disrupted halo. IC 412 right next to it [34”], faint and also small, and seems to be an interacting system. Star very near the northern edge. [It is indeed interacting, VV 225 – and tidal tail north of IC 412 might be visible with more concentration – need to revisit].

HGC 34 = Arp 327: The brightest component, a, is NGC 1875 and was round, very faint, very small. After looking at my Hickson guide photo, I tried very hard to see the very small 17-18B mag b-d components; at 553x I still could not make them out; I had a feeling of an excessively faint streak coming off NGC 1875 to the southeast, but this was probably wishful seeing since I had already studied the photo. 419 mly.

After a break I changed directions to the north to take in some galaxies in Ursa Major:

NGC 2805: Astonishing field, and quite a change from viewing many dim objects. NGC 2805 is a large, fairly faint oval, brighter core but without nucleus, mottled – hint of spiral arms [it is an Sc]. 10’ to the NE are three more galaxies: NGC 2820 is a long edge on, pretty bright with a brighter sliver of a core and long tapering tips, ENE-WSW 5:1. At first I thought the SW tip had a hook to it pointed SE, but this is IC 2458, a small, faint elongation, and it overlaps the 2820’s SW tip, like the Hockey Stick galaxy (NGC 4656/57 in Canes Venatici). NGC 2814 is to the west of this pair, small, faint, elongated 3:1 NNE-SSW, with a star just to its SW. All three are interacting with each other, along with NGC 2880 and IC 2458 which I didn’t observe.

NGC 3079 offered up another amazing view. It is a long, lovely bright edge on 6:1 N-S with plainly seen turned up tips: the southern tip lifts east, the northern tip lifts north-east.  This makes it look like the galaxy is descending through space, with the perimeter of the halo being swept upward as it falls.  NGC 3073 was to the west in the same field, and was pretty bright, small, round, with a bright core and hazy fringes.

NGC 2756: Oval, 3:2 N-S. Brighter core, no nucleus. Mottled; seems to be a dark lane running N-S along the eastern hemisphere. [It is an Sb spiral, so this may have been a hint of arms.]

Shakhbazian 98: NGC 2675 was easily visible (pretty faint, small, obround, even surface brightness elliptical) and served, along with a pair of stars to the east, as a finder for the Shk 98 galaxy chain. I searched a while but did not see anything on my own. After checking a finder for the group, which are eight very small and very faint galaxies forming a gentle sickle between the galaxy and pair of stars, I searched again, switching between 333x & 553x. I wish I could say I saw it but no; my eyes were pretty strained at this point in the night.

NGC 3756: Large, 3:2 N-S, fairly bright with a brighter core. The halo is layered like filo dough—striking texture in the halo giving strong impression of wispy thin spiral arms [ScII]. Double star off the northern tip to the north-west.

NGC 3738 = Arp 234: Rather large, moderately bright, 3:2 NW-SE, with a distinctive tear-drop shape—the core appears brighter and rounder to the NW, while the SE tip curves up from the core and tapers off. Is an active galaxy nucleus.

NGC 3733: 5.6 magnitude star SAO 28064 interferes with the view; the galaxy sprouts from the star as a 3:1 elongated glow NNW-SSE with a slightly brighter core. Too bad; the galaxy is Sc spiral and would probably show nice structure if it weren’t for the star being in the way.  Maybe wait a few thousand years for a clearer view!

NGC 3687: Small, pretty bright, 3:2 N-S. Seems to have a dark lane running its major axis. The whole brightens with averted vision. [As a pretty much face on spiral it should be round; I may have not seen some sections of the outer halo to give it an elongated shape; the dark lane may have been hints of spiral structure.]

NGC 3359: Large, generally round diffuse halo, stellar nucleus and a brighter core which runs in a bar NNE-SSW. Halo appears windblown and tattered. It is a SBc II spiral, however I did not discern the arms, only the impression of disarray in the halo.
Mark

sgottlieb

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Re: galaxies galore
« Reply #1 on: January 04, 2017, 10:23:50 PM »
Fantastic set of observations, Mark!  You obviously stayed up late to catch all those spring galaxies (unless they were rising in the east), so I'm guessing you put in quite a number of hours.

UGC 3258 is really strange one on the SDSS -- a barred spiral with ring?



UGCA 102 is a peculiar irregular



NGC 3079 is a great object as your description shows, but it's near a rare object -- the celestial doppelgänger Twin Quasars, situated 14.2' NNW (visible as a faint, close double right at the top edge of the SDSS image) of NGC 3079.  First lensed quasar discovered in 1979.  The two images of the quasar are quite faint at V = 16.6 and 16.8 with a separation of 6".  I can glimpse it in my 18-inch, but not see both components simultaneously.

« Last Edit: January 05, 2017, 09:19:40 AM by sgottlieb »

DDK

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Re: galaxies galore
« Reply #2 on: January 06, 2017, 12:45:47 AM »
Evocative report, McCarthy, some set of galaxies indeed!
Got me to go back over my notes for comparisons on objects I remembered seeing, and didn't remember (yeah 2805).

Fun that you saw a different neighbor of 2805 than I did when I was in that neck of the woods, with Uncle Albert the 16” (now Dan Wright’s scope), just about 2 years ago at the Peak. I found 2880, while you saw 2820, which I didn’t.

My notes show differences in telescopes and in the nights. My 16, your 20, and that night at the Peak wasn’t the best Peak night, with limiting magnitude at 5.5. Seeing was good, 4/5. Funny notes on both those galaxies - for 2805, “very dim, barely there in 9mm. Low SB (no shit). Persistent shape in 7mm, maybe oval at 45°.” The PA is actually 125°, I was way off, and the surface brightness really is registered at 14.6. Woof.

Went next to 2880, just next door, “to south of 2805, better. Got my faith back. Round with stellar core, fairly bright, compact.”
Good comic relief, after its neighbor.

3079 is a favorite, highly recommended for any telescope. Hey, maybe a third endorsement will get someone to go there. My notes in Felix, my 11”, sure got enthusiastic, starting in August ‘04, yes from the Peak - “Sketched, on the TAC Eye Candy List, long, big, could just make out core, while 3079 was far into the West. Look again!

“Bob Czerwinski had shown this one off 2 Feb ‘02 at Dino. Gorgeous, lanky and complex.

“5 March 05 back here, lovely long feathery spindle. Mottling throughout. Running N-S ca 8’ long in 6 mm (yes!).”
Here I got the PA and the length pretty much right.

Seeing the WLM was a big deal to me. Just the name makes it sound all mysterious. And I’ve made a project of finding every galaxy in our Local Group possible in medium aperture, now have 16.

This was in 2007, again from Fremont Peak. Got a compliment from The Animal when I posted the OR, Steve saying, “Nice catch.” This was also in Felix my 11” -
“Oval band of mottling that stuck around at the edge of averted vision, with the right size and N-S orientation, in the right location. Sketch matched starfield in NED pictures. Wrote ‘maybe the right mottling.’ “
One more subtle pleasure.

Thanks for your writeup.
TAC - astro anarchy at work <*>

sgottlieb

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Re: galaxies galore
« Reply #3 on: January 06, 2017, 12:17:24 PM »
Here's a recommendation to put NGC 2820 on your "To Do" list, Jamie.  The challenge is really the attached companion that Mark mentioned -- NGC 2820A.  I saw it ages ago in my 17.5", but never tried in a smaller scope.  It's really an attractive pair in my 24".

24" (2/22/14): fairly bright, very large, very thin edge-on 7:1 WSW-ENE, ~2.8'x0.4', very weak concentration, mottled appearance though the surface brightness is not high.  NGC 2820A dangles just south of the west-southwest edge.  It appeared faint, small, oval 3:2 SSW-NNE, 18"x12", occasional stellar nucleus.  NGC 2814, a smaller edge-on, lies 3.7' W.