Object of the Week June 2, 2013 Hoag,s Obect (The king of the rings)

Hoag Object (PGC 54559)

Serpens

Ra
15 17 14
Dec
+21 35 08

Mag 16.4 ?

Type Ring Galaxy

I have been fascinated by this galaxy since the first time I saw the image of it taken by the 200" Hale telescope many years ago. This galaxy started my quest to see as many ring type galaxies as I could find and to catalog them.http://www.faintfuzzies.com/Files/RingGalaxies%20v4.pdf

So what is this strange type of galaxy? That is a good question and as of this date the pro's are not sure ether. Art Hoag first publish a paper about this object in 1950 he first thought it to be a plantary nebula but had suspicion that it was a galaxy. The two best guesses is that it is a bared ring and the bar has deemed down and the other is its a old merger event of a S0 type and a spiral galaxy millions of years ago. Hoag object is 600 million light years away and a little bigger than our milky-way galaxy.

I have observed this strange ring many times over the years and to see the ring is a tough challenge that takes a large telescope and dark steady skies. On most nights with the 48" it just pops in every now and then in moments of good seeing. But to see the core I have seen a report from Sue French that she has seen the core in her 10" as very faint dim glow. There is a fish hook of stars that I us to ID the field when I am looking at Hoag's (see the image below.)

Attachment 690

So if you want to see a very unusual type of galaxy be sure to track down Hoag's Object and if you only see the core you still will have seen one unique and strange object.Attachment 691


And as always be sure to

"Give it a go and let us know!"

Good luck and great viewing!

Jimi,

I tried the ring with 16" and my 27".

With 16" I could saw a glow with a very faint spot in the middle. I explain the observation that I could pick up the core as a stellar brightness and the ring as the faint glow around it. In contrast to other observations with similar aperture the ring should not be visible as a glow. After the observation with 27" I am sure that the observation was for real.

16", 180x-360x, NELM 7m+
Attachment 694

With 27" the central core was easily visible with direct vision. The glow around it was also not very difficult. Two other observers and I could see a faint glow which we could hold with averted vision. There was no dark space between the glow and the core although the contrast could pretend this. All in all the ring as a ring itself was not visible for me.

I've had a good look at Hoag's Object with my 28 and Jimi's 48 and also have not seen the outer ring as a distinct ring. In my 28 the galaxy looks like a planetary nebula and the "ring" is seen as a round, diffuse glow around the core, but only with averted vision.

Attachment 703

This sketch was drawn under nearly ideal conditions at 408x but with Hoag's Object poorly placed in the western sky.

The next sketch was drawn using Jimi's 48" this past April:

Attachment 704

The magnification was 488x and the conditions also very good but with Hoag's Object much better placed - but still a full ring was not seen, just a diffuse glow with a bit of ring segment on one side. Perhaps if we had tried different magnifications and spent an hour or so observing it the full ring may have become apparent, but the lesson here is that although a round glow is fairly easy to see, the ring is not.

Howard I have a new for me 1998 model Starmaster 11" that has a good mirror. It will be fun to try for Hoag's core with it at GSSP .

I observed Hoag's Object from High Knob Overlook in North Central PA this past Saturday night. Seeing and transparency a decent 4/5, SQM of 21.29 at the time of observation.

I was unable to resolve the ring or detect the general glow noted on this thread but I was able to detect and hold the bright core with averted vision. This at 351x with a 6mm Delos. Am thinking I'm going to need truly remarkable conditions to resolve more than I'm already seeing with Ursa. Either that or a mirror stretcher... :cool:

Have marked this to be reobserved during my next session. Don't think it's going to be this month. Hopefully July...

As an aside... I did try using my 6mm UO Ortho. This as an ongoing comparison between my Delos and Ortho EPs (in response to another thread). I honestly didn't see enough of a difference between the two to make me want to start using Orthos instead of the more comfortable Delos. I think the bright core was (perhaps) a tick steadier with AV. When I was doing comparisons between Naglers and Orthos, the difference seemed apparent and repeatable. Am not seeing that with the Delos/Ortho comparison.

Lou,

Glad you were able to catch the core of Hoag's. Keep at it you never know when the right night will come along. Its still pretty cool to see any part of this very very unusual galaxy.:D

Quote:

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Originally Posted by Jimi Lowrey

Howard I have a new for me 1998 model Starmaster 11" that has a good mirror. It will be fun to try for Hoag's core with it at GSSP .

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Hey, that should be fun scope Jimi, and I'll bet we'll see Hoag's core with it at GSSP if we have decent skies. We've had very nice spring weather up here the last two months so hopefully early summer will be just a s nice.

Update - I was able to see the ring of Hoag's Object at the GSSP a couple weeks ago with my 28". Jimi saw it as well and we were pretty darn excited. The ring came and went with the seeing and even when it did pop into view it was a relatively subtle brightening of the perimeter of the round glow around the core of the galaxy. The core and round glow were always visible though. Here's my notes and sketch:

"WOW! I could barely discern the ring a few times with extreme averted vision with both the straight 8mm Ethos and Jimi's 6mm Zeiss (no Paracorr) and the ring "popped" in both eyepieces a couple of times - how about that! the rest of the time I saw a circular glow around a star-like core, but the perimeter of the glow quite distinct. Jimi also saw the ring pop with his 6mm Zeiss a few times too. This is a very cool observation! 21.63 SQM. (PS, just tried Jimi's 7mm Takahashi - very nice eyepiece with excellent contrast - but no pop. But then I put the Paracorr back in with my 8mm Ethos - 408x - and the ring popped again!)

Attachment 767 Attachment 768

Now that I've seen the ring I think it would stand out fairly well in really steady seeing, given a dark and transparent sky, but it will always be a subtle brightening of the perimeter.

I was totally surprised to see the whole ring structure in Howard's 28"at GSSP. Howard and I were viewing Hoag's object and could only see the core so I ask if we could try my 6MM ZAO Howard put it in and I settled in to the view and "BAM" the whole ring popped into view. This happened several times and Howard tried it and had the same experience. We were both very excited. This was one of the highlights at GSSP for me.