Object of the Week May 6, 2012-UGC 9242 (Looking for the flattest of the flat)

UGC 9242

Super-thin Galaxy

Bootes

J2000
RA 14 25 20.9
DEC+39 32 22

MAG 14.1

Axial ratio 21.3

I have always really liked flat and super-thin galaxies and as far as I know this is one of the flattest know in the spring sky. I will add others as the seasons move along for the summer, fall etc.

what I am on a quest for is to find the Flattest of the Flat in the night sky. So if you know of a flatter galaxy in the spring sky please post it her. This should be a fun quest and I look forward to you're input.
Attachment 210
Attachment 211

So remember the next time you are observing near Bootes try UGC 9242 I think you will like this long ghostly streak and,

"GIVE IT A GO AND LET US KNOW"

GOOD LUCK AND GREAT VIEWING!

This sounds great, thanks.

The only ones in that league per a crunch of the Astronomical League's Flat Galaxy list are these two
UGC 12281 This is really a summer object with mag 14.9 located at 22 59 12 +13 36 18 (near that wonderful Ngc7479) and has an elongation ratio of 17.2 where Ugc 9246 is EL ratio of 16.6

If you are well south IC 4871 in Pavo has EL ratio of 16.7 but is at 19 35 42 and 'a bit TOO low' at -57 31 06 (it can just above Jimi's or the just over TSP very low horizon)

I expect Alvin will chime in as he likes these ultra-edge on flat galaxies and has his own guide.

Jimi,

with 16" I could pick the galaxy easily but without the extremely flatness. I only could detect the brighter central region with perhaps 4:1 E-W. The outer regions were to faint. I have to give a try with the 27", thanks for the OOTW.

Flat galaxies are some of my favorite targets and this makes for a great choice for an OOTW!

And for those who don't know, Alvin Huey has a fantastic downloadable observing guide dedicated to flat galaxies on his website www.faintfuzzies.com In it you'll find over 170 targets!

Along with all his other downloadable guides, you can find it here

Jimi,

yesterday I tried the galaxy a second time with my 14,5" and what a big surprise. The galaxy could be detected with direct vision. With averted vision and 141x (AP 2,7mm) the galaxy went to an incredible thin streak with approx 8:1 elongation. 202x was also a good choice but the best view was still in the 10mm XW (141x). Very cool OOTW!

My observation with my 22" under NELM 6.5 skies

22” at 185, 255, 306 and 383x – Considerably faint, very thin and long glow with defined edges. Brighter slightly elongated center. A 12.4 mag star lies 1.3’ SE from the center. PA = 60 and 3.1’ long.

Perhaps a little late in the season, but... while compiling observation guides for 8-10" scopes I ran into a thin little fella: NGC3245A in Leo Minor. Attachment 242
Too faint for an 8-10" scope, but worth mentioning. While the axial ratio is smaller than that of MCG+07-30-011 (UGC9242), 10.7 vs. 15.8, it is jùst a hair thinner according to NED data:

NGC3245A, 3.64 x 0.34
MCG+07-30-011, 5.69 x 0.36

So flatter? Yes, although MCG+07-30-011 may appear flatter visually due to its size and uniform brightness.

I'll post again should I run into one that's even thinner.

Cheers,


Victor

Also one of my favorite edge-ons. I included UGC 9242 in an article I wrote on superthins in the May 2011 issue of Sky & Tel, but unfortunately it was edited out because of space limitations for the column.

So, here's the missing paragraph --

UGC 9242 is a paper-thin 5.6' x0.3' streak, located 1.8° northwest of 3rd magnitude Gamma Bootis. The surface brightness of UGC 9242 is quite low and dims out at the tips. Using 285x, I could only trace the length to 3'. A 12.5-magnitude star, just 1.4' southeast of the geometric center, helps pinpoint the location.

One more tidbit on UGC 9242 ----

I took another look at this razor-thin a few nights ago with my 24-inch along with Jimi Lowrey at the Golden State Star Party in northern California. Jimi noticed a faint galaxy 4' NE that was missed by Larry Mitchell when he compiled the MACs in Megastar. It was picked up in the 2MASS survey as 2MASX J14253327+3935298 and is now in LEDA as PGC 2152475. The galaxy was just a round 10" glow, but was not difficult (visible continuously with averted).

When I checked my earlier notes of UGC 9242 today, I noticed Jimi and I took a look at UGC 9242 with his 48-inch scope last April 4th and of course I had already logged PGC 2152475, but had completely forgotten!

Working out observations from the night of 27-28 April 2022, this topic came to mind as it did to me, too, at the eyepiece that night.

Another very flat one: MCG+04-29-060 (PGC39432, UGC7321). It was mentioned before on this forum in this post: https://www.deepskyforum.com/showthr...ull=1#post4111

Attachment 4757

Attachment 4758

Here it is in Aladin.

NED gives it a dimension of 6.74 x 0.43 minutes of arc. That's a ratio of 15.7.

For the galaxy that was the subject of this topic, MCG+07-30-011 (Holmberg 643A, Zwicky I 88, PGC51503, UGC9242), NED states 5.69 x 0.36. A ratio of 15.8.

So it's a very close second!

This is what I observed using my 14" SCT @ 168x / 29':

A very faint but clearly extremely elongated line (can't call it a streak), even in brightness, at the limit of visibility without AV. With AV subtly brighter west of the middle in a central part that is elongated in the same direction.

To the east, in line with the galaxy, is a mag. 13.5 star.

Give this one a go, too, next spring!