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View Full Version : Object Of The Week May 12, 2019: NGC 5248



wvreeven
May 13th, 2019, 08:16 AM
NGC 5248, Caldwell 45, UGC 8616, MCG+02-35-015, PGC 48130

SAc C, Galaxy in a group of galaxies

Constellation: Bootes

RA: 13 37 32.069
DEC: +08 53 06.22

Visual magnitude: 10.2
Dimensions: 6.2' x 4.5'

This galaxy is bright enough to make some people wonder how Messier could have missed it. As most of us probably know, Messier actually observed comets and only happened to come across (what we now know are) deep sky objects when a comet would pass by them. Apparently no comet ever came close to NGC 5248 so that's why Messier didn't observe it. And the fact that Messier didn't observe it was a good excuse for Sr. Patrick Moore to add this galaxy to his Caldwell list of objects.

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Image taken from Wikipedia

NGC 5248 is a beautiful spiral galaxy for which astronomers seem to disagree on its actual type. Simbad classifies it as SAc C (quoted above) however NED classifies it as SAB(rs)bc with (R)SB(rs)bc and Sy2HII as alternatives. So, they all agree that this is a spiral galaxy but whether it has a bar (B) and/or a ring (r), it is compact (c) or even a Seyfert galaxy (Sy) is not exactly clear. What do you think?

NGC 5248 is the main member of the NGC 5248 Group, which also contains UGC 8575 and UGC 8614. The NGC 5248 Group itself is one of the so called Virgo III groups. The Virgo III groups are a chain of galaxy groups that extend from the Virgo cluster.

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Image taken from Atlas Of The Universe

This arguably is one of the most direct and obvious ways of seeing clustering and filaments of galaxies in the sky. Plus it is a great resources of relative close by galaxy groups which should keep you busy for a few nights if you plan to observe them all.

My observation notes of NGC 5248 from May 15, 2015, using my 20" telescope are rather limited since I observed it at a night of poor seeing so I couldn't use a high magnification. Still, I was very much impressed by this galaxy:

"At 151x a beautiful oval glow with a stellar core. The core is embedded in a globular glow from which two spiral arms run away. Spectacular."


As always,

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

obrazell
May 13th, 2019, 02:47 PM
Do you really want to do this one Wouter as it has been in the OOTW in both 2015 and 2017.

Owen

wvreeven
May 13th, 2019, 04:12 PM
Aaarrghhh thanks Owen! I failed to notice that. I’ll do another object tomorrow. Sorry!

Jimi Lowrey
May 14th, 2019, 01:39 AM
It is a beautiful image of 5248 :D

wvreeven
May 15th, 2019, 06:40 AM
I don't want to add a new thread to the "Object Of The Week 2019 (OOTW)" forum because that would mess up the nice structure ;) So I'll add my new post here as a comment:

Object Of The Week May 12, 2019: NGC 5676

NGC 5676, UGC 9366, MCG+08-26-043, PGC 51978

SAbc C, Galaxy in a group of galaxies

Constellation: Bootes

RA: 14 32 46.853
DEC: +49 27 28.11

Visual magnitude: 9.78
Dimensions: 2.54' x 1.17'

This is a pretty spiral galaxy without a bar at its center. Hence the "SA" type designation. The "bc" part indicates that its spiral arms are pretty loose to loose and the core small to compact.

One of the most striking features of the galaxy is that it is asymmetric as can be seen it this SDSS image.

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The northern arms are well-defined whereas the southern arms are very patchy. The disk of the galaxy is symmetric but the most northern part lacks any distinct spiral features whereas the southern arms extend into the most southern part of the disk. The patchiness most notably of the southern arms led for this galaxy to be classified as a flocculent galaxy.

The northern arm also contains a very prominent star forming region, which also is the brightest source of infrared radiation in this galaxy's disk.

My observing notes of this galaxy are pretty coarse because I observed it on a night of bad seeing. Still, I was able to make out most of the features of this galaxy:

"At 151x a pretty, elongated glow with a stellar nucleus. To the north of the nucleus lies a bright patch. The disk of the galaxy appears blotchy."


As always,

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

andre8x8
May 15th, 2019, 05:39 PM
Hi Wouter,
The attachment doesn't seem to work.

wvreeven
May 15th, 2019, 05:50 PM
Thanks Andre. It is fixed now.

Raul Leon
May 16th, 2019, 01:05 AM
Hi,
Here's my observation from 5/16/2015 on ngc 5248 ; magnitude:10.3 size; 4.1' x 2.1' ; bright , large and elongated. Bright nucleus with some mottling towards the arms. I used a 10mm Ethos at 158x with my 14.5 Starstructure Dob f/4.3 3532

Raul Leon
May 16th, 2019, 01:17 AM
Hi again,
This is my observation from 6/3/2016 on ngc 5676 galaxy in Bootes; magnitude:11.09 size:3.6' x 1.6' fairly bright and elongated with a bright oval central nucleus ; faint star along North side of halo . I used a 8mm Ethos at 198x with my 14.5 Starstructure Dob f/4.3 3533

roragi
June 19th, 2019, 03:14 PM
This galaxy is visible its structure in my old refractor TV genesis of 4 ''. the shape of S is visible in a sky of nelm 6.5 SQM, 21.6 the transparency and seeing is good 4/5. The nucleus is dominant and somewhat elongated, the image is somewhat dirty but it is not difficult to see its structure if the night and the place is good, I still have my image stuck in the retina at the end of May 2014.

Roberto.