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Starhopping to NGC 7331 and the Pegasus galaxies.

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#1 AndrewJ

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Posted 26 August 2009 - 11:34 AM

I have twice found a very attractive galaxy outside the Pegasus square (above in Northern Hemisphere skies) toward Lacerta. I think that this may be NGC 7331 which I was seeking. However, I only seem to find it by accident so cannot be sure it is not 7217 or some other! I have not been able to starhop there from any major star. :foreheadslap: The field I see in my 8" dob is quite different from my map.

Am wondering if anone else has found 7331 to be a difficult star hop. I like to use the astrosurf.com finder maps you get through a google image search.

I know this is a somewhat specific issue but I thought that this might be the right kind of forum.

#2 MikeRatcliff

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Posted 26 August 2009 - 02:31 PM

I do more of a "star jump" using a Telrad and following a line extending from mu Pegasus through Eta Pegasus extending towards Lacerta a distance of about 2/3 of the distance between mu and Eta. That puts me in the ball park and a quick skim around finds it.

Mu and Eta are bright and easy to find, making a triangle with Beta, one of the corners of the Pegasus square.

Hope that helps.

Mike

#3 bicparker

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Posted 26 August 2009 - 03:19 PM

Mike's description is about the best way to find it. With practice you will nail it every time.

Since 7331 is about 4 degrees from Eta, I put my Telrad about half a Telrad out from Eta more or less along the line described by Eta and Mu.

Stephan's Quintet is pretty much south (and just slightly west) of 7331 about 29-30 arc minutes (i.e., half a degree). This is where knowing your eyepiece TFOV is handy. When I use my 26T5 on my 17.5" dob, for instance, I know it has nearly a degree FOV (~.95 degree), so when I move a bit over half an eyepiece FOV to the south, I should be able to see the faint mess that is Stephan's Quintet. At that point, I add the appropriate magnification and, Voila! Galaxies!

If you are seeing 7217, then you are way off target. They should look distinctly different. 7331 will be brighter by comparison and will appear oblong or as an angled edge on spiral as opposed to 7217, which will appear round.

Time on task will make these guys easier every time.

#4 AndrewJ

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Posted 26 August 2009 - 09:29 PM

OK, I'll try cutting the length of the star hop by placing my red dot more ambitiously. 7331 would be a great Fall galaxy to be able to quickly show people - recognisably a galaxy yet sufficiently obscure and seriously distant and redshifting.

Will try again on Thursday (no need to hold your breath ;)).

#5 rocco13

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Posted 26 August 2009 - 10:36 PM

SkywardEyes has a website with this very subject discussed, with a picture of these galaxies, and describes the task of 'hopping' to Stephan's Quintet from 7331.

http://skywardeyes.webs.com/apps/blog/

(about halfway down the page)

This taught me something as I thought those faint companions of 7331 WERE the quintet!

#6 Dave Mitsky

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Posted 27 August 2009 - 02:36 AM


Stephan's Quintet is pretty much south (and just slightly west) of 7331 about 29-30 arc minutes (i.e., half a degree). This is where knowing your eyepiece TFOV is handy. When I use my 26T5 on my 17.5" dob, for instance, I know it has nearly a degree FOV (~.95 degree), so when I move a bit over half an eyepiece FOV to the south, I should be able to see the faint mess that is Stephan's Quintet. At that point, I add the appropriate magnification and, Voila! Galaxies!


I had a rather interesting simultaneous view of Stephan's Quintet and NGC 7331 on Monday night through Robert Werkman's 18" Obsession and a 17mm Tele Vue Ethos.

Dave Mitsky

#7 FJA

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Posted 27 August 2009 - 03:06 PM

SkywardEyes has a website with this very subject discussed, with a picture of these galaxies, and describes the task of 'hopping' to Stephan's Quintet from 7331.

http://skywardeyes.webs.com/apps/blog/

(about halfway down the page)

This taught me something as I thought those faint companions of 7331 WERE the quintet!


That's a really handy pic that Kevin's posted on his site there. I have saved it (I hope that's ok, Kevin?) and will use it to track down the Quintet this autumn. I have seen it before, through a friend's 14" SCT sometime back in the 1990's, but I would like to track it down myself and see it from my own backyard, especially now I have a big scope again. :grin:

#8 7331Peg

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Posted 27 August 2009 - 07:39 PM

Managed to coax four of the five members out of my six inch refractor last night with a 6mm Ethos and a 5mm Radian. Transparency was about eight on a scale of ten. The largest, NGC7320, was easy to see. The others were there, but you had to look closely. On nights of good transparency, using a 13mm Ethos, I can catch a glimpse of them in the same field as NGC7331. Given decent transparency, they're fairly easy to see if you know exactly where to look.
Which is true of most anything, for that matter. :jump:

John

#9 AndrewJ

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Posted 28 August 2009 - 10:17 AM

Last night I nailed the star hop from Eta Pegasi (I'm sure that's a weight off all your minds), still think it's an awkward one but useful what with Stephan's Quintet handy.

Also noted M32 and M110 and Uranus for the first time. A good night.

#10 FJA

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Posted 28 August 2009 - 10:46 AM

Hoping the weather will be clear tonight and I can get out with my 12". The forecast looks good as far as clear skies are concerned (and it should be nice and transparent as showers have just passed through) but the wind is currently gusting at 30mph. Think I'll need to find a sheltered spot with a good view of the eastern sky...

#11 F.Meiresonne

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Posted 30 August 2009 - 04:19 PM

Good luck , Jordan,
However it't rather difficult i think. I saw it once over here at our dark spot and some days ago in the Provence. The Quintet is rather easy to spot but it's difficult to make out all the members. Off course in the Provence it was not yet high up...
You sure need a clear night...

#12 FJA

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Posted 30 August 2009 - 05:46 PM

I got the Quintet the other night. The sky cleared off beautifully and I set the 12" scope up in a sheltered corner between the house and shed.

The notes I made as as follows:

"Hickson 92/Arp 319 - Stephan's Quintet, galaxy group in Pegasus.
Finally found Stephan's Quintet with my own scope (I have seen it through other scopes in the past, but not found it myself). I have looked for this in the past, probably over ambitiously, with my 8" from here and - maybe unsurprisingly - saw nothing, although I have read reports of people getting this group with scopes as small as six inches aperture (but they were under Arizona skies and not humid, particle laden UK ones). It is a short star hop just south west of NGC 7331.
Through the 12" the group was faint and I saw the five (if NGC 7318A and B are counted as two and not one) members with averted vision, two reasonably 'bright' and the others fainter. These were NGC 7317, NGC 7318 A/7318B, NGC 7319, NGC 7320. I put the magnification up to 190x to darken the sky and this paid off with a better view of the group."

Can someone tell me if NGC 7318A and 7318B are counted as one, or two objects? If they're one, then I only saw four. :p

I am going to re-observe this the next clear, moonless night. We have now moved into a period of bad weather which is no problem as the Moon's getting fat again.

#13 MikeRatcliff

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Posted 30 August 2009 - 06:16 PM

Last night I nailed the star hop from Eta Pegasi (I'm sure that's a weight off all your minds), still think it's an awkward one but useful what with Stephan's Quintet handy.


Congrats, Andrew! Yes you are right it is a bit awkward, aren't many good guide stars between Eta and 7331.

Mike

#14 MikeRatcliff

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Posted 30 August 2009 - 06:28 PM

Can someone tell me if NGC 7318A and 7318B are counted as one, or two objects? If they're one, then I only saw four. :p


Cygnus,

It's counted as two galaxies. I have had trouble splitting them at times though.


Congrats on finding it!

Mike

#15 FJA

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Posted 30 August 2009 - 06:42 PM

Thanks Mike.

#16 AndrewJ

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Posted 30 August 2009 - 09:15 PM

Whilst I was at 7331 the other night I tried Stephan's Qunintet in our 8 inch but like Cygnusx1 feel it may be beyond that aperture. They may be just too distant. I am cautiously optimistic that the Pegasus I cluster may be achievable in the 8 inch from my back yard (would be my first galaxies outside of our Local Supercluster).

#17 7331Peg

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Posted 31 August 2009 - 06:56 PM

They're not too distant for an eight inch, but they will require very good transparency and dark skies. Even then, you'll only see a couple of faint hazy patches. Having an excellent reference photo or chart to work with is half the battle. I've found that it is actually easier to see Stephen's Quintet than two of the faint galaxies, NGC 7340 and 7336, surrounding NGC7331.
On another note, I was able to just barely separate NGC 7318A and B in a C11 on a very good night at about 180x.

John

#18 David Knisely

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Posted 31 August 2009 - 10:15 PM

Whilst I was at 7331 the other night I tried Stephan's Qunintet in our 8 inch but like Cygnusx1 feel it may be beyond that aperture. They may be just too distant. I am cautiously optimistic that the Pegasus I cluster may be achievable in the 8 inch from my back yard (would be my first galaxies outside of our Local Supercluster).


Stephan's Quintet is within range of a decent 8 inch under fairly good conditions (ZLM 6.0 or fainter). After being shown where to look in a friend of mine's 10 inch f/8 Newtonian many years ago, I quickly found them in my 8 inch f/7 not long afterwards. They appear as a small very dim somewhat lumpy patch, as it is difficult to pick out their individual members. In my 9.25 inch SCT, I can usually identify four of the five members with some certainty. As for Pegasus-1, it actually isn't that hard from a dark sky site, although only about two of the galaxies stand out to any degree (NGC's 7619 and 7626). At the Nebraska Star Party, I had fun going through the group with my 9.25 inch SCT and finding between 10 and 12 of the member galaxies at around 100x and then going over to John Johnson's 20 inch Obsession to really get a good look at all of them. Clear skies to you.

#19 Dain

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Posted 01 September 2009 - 12:11 AM

This fine galaxy group ( including 7331 ) are great targets for an 8" dob under favorable conditions. I've nailed just about all of the aforementioned and have them down in my notes from my local observing site. Funny thing is, in my years of observing I don't think I've seen this group in big aperture yet.

Clear Skies to You All!

#20 AndrewJ

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Posted 01 September 2009 - 11:48 AM

As for Pegasus-1, it actually isn't that hard from a dark sky site, although only about two of the galaxies stand out to any degree (NGC's 7619 and 7626).


I'm really only expecting to see 7619 and 626 through an 8 inch (although more would be great). I've learnt the hop already - there's a group of five below the right side of the Pegasus square which I think of as shaped like a paw. One side of "the paw" points to a star visible in the finder and Pegasus I should be right there.

#21 Scanning4Comets

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Posted 16 July 2013 - 04:08 AM

I've tried for Stephan's Quintet dozens of times with no success. I am going to print out a good pic of 7331 and Stephan's and hunt it down next time I am out and the sky is really good, (Mag 5.2 skies or just over that), with no moon at all.

Cheers,






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