7 replies to this topic

[Carolina Observer]

My final observing notes for the Deer Lick Galaxy Group and Stephen's Quintet in the following link.  My 30 year goal has been to see all three galaxies, known as the Deer Lick Group from my suburban backyard  and with a 10-inch Newtonian.  

 

https://rogerivester...north-carolina/

 

The following link is my 15 plus year astronomy blog "and other" which represents my 40 years as a serious student of amateur astronomy:

 

https://rogerivester.com/

Edited by Carolina Observer, 30 November 2024 - 01:29 PM.

[Kitfox]

Another good read.  10” is tough for these. My old eyes need 18”   And still they’re “did I really see more than one?”  

Edited by Kitfox, 30 November 2024 - 12:12 PM.

[bphaneuf]

Terrific work Roger.  With those optics and under skies as bright as that it speaks loudly to your observing skill and patience.  Well done sir

-b

[Starman1]

My final observing notes for the Deer Lick Galaxy Group and Stephen's Quintet in the following link.  My 30 year goal has been to see all three galaxies, known as the Deer Lick Group from my suburban backyard  and with a 10-inch Newtonian.  

 

https://rogerivester...north-carolina/

 

The following link is my 15 plus year astronomy blog "and other" which represents my 40 years as a serious student of amateur astronomy:

 

https://rogerivester.com/

But there are 4 galaxies almost the same size and brightness near NGC7331:

NGC7335 / 7336 / 7337 / 7340

7336 is the faintest overall at mag.16.8, but due to its small size has a surface brightness of m.12.5 and is visible in my 12.5" in 21.4 skies.

7337 was tougher.

Surface brightnesses are:

7335  12.9

7336  12.5

7337  13.9

7340  12.8

The hardest to see in my scope is 7337, showing that surface brightness counts.

My first observation of all 4 was with an 8" scope.  They form a quadrilateral.

 

I see you saw them from a suburban back yard.  That's quite a feat, given how small and faint they are, with a 10".

Darker skies would likely reveal 5-6 galaxies in Stephan's "Quintet" as well.

That you could even see a glow in that location shows a lot of perseverance in your observing.

 

Simply excellent.  I suspect we'd all be amazed how deep you could go in really dark skies.  Kudos.

Edited by Starman1, 30 November 2024 - 03:43 PM.

[Kitfox]

But there are 4 galaxies almost the same size and brightness near NGC7331:

NGC7335 / 7336 / 7337 / 7340

7336 is the faintest overall at mag.16.8, but due to its small size has a surface brightness of m.12.5 and is visible in my 12.5" in 21.4 skies.

7337 was tougher.

Surface brightnesses are:

7335  12.9

7336  12.5

7337  13.9

7340  12.8

The hardest to see in my scope is 7337, showing that surface brightness counts.

My first observation of all 4 was with an 8" scope.  They form a quadrilateral.

Do you recall what magnification you were using in the 12.5”?  I have resigned myself to the knowledge that a 6mm exit pupil is probably going to be wasted light for me now, and I know it’s a balancing act between size and surface brightness. I have an 11” Zambuto and a 12.5” Ostahowski I want to test my limits with..

[Starman1]

Do you recall what magnification you were using in the 12.5”? I have resigned myself to the knowledge that a 6mm exit pupil is probably going to be wasted light for me now, and I know it’s a balancing act between size and surface brightness. I have an 11” Zambuto and a 12.5” Ostahowski I want to test my limits with..

I had a great view of all 4 at 183x with a 10mm Ethos in the 12.5". Today, I'd use a 9mm Morpheus at 203x due to the light pollution increase over the last 14 years. You need a black enough background but not too high a power.

[Redbetter]

There are actually six galaxies relatively near NGC 7331 that are of reasonable magnitude.  The other two are to the NW of the galaxy.  One, PGC 69291 (sometimes listed as NGC 7327) is somewhat masked by a star about 5" from its center.  The other, CGCG 514-66 (PGC 69281)  is sometimes misidentified as NGC 7326 (as in the RNGC and Wikisky) per Steve Gottlieb's NGC notes. 

 

I observed both of these latter galaxies on 8/19/22 with the 20" along with the NGC 7331-dwM which is much more challenging.  This low surface brightness dwarf galaxy (aka PGC 2059185) is a true satellite of NGC 7331, unlike the others.  A paper about the NGC's dwarf galaxies listed it as 16.15 visual mag.

 

The "flea" magnitudes have been discussed before.  NGC 7336 is much brighter than some sources give, mid-14's, not high 16's.    Here are the magnitudes and surface brightnesses of the fleas from Uranometria Deep Sky Field Guide, converting from the obsolete mspam reporting to mpsas--which is far more useful, not easily confused with apparent magnitude, and directly relatable to measured sky brightness since they share the same units.  For a visual observer mpsas is just so much more practical than mpsam.

 

Galaxy             TIM        Surface brightness (mpsas)

NGC 7335       13.4        21.9

NGC 7336       14.5        22.0

NGC 7337       14.4        22.9

NGC 7340       13.7        21.9

Edited by Redbetter, 01 December 2024 - 03:01 PM.

[Carolina Observer]

In November 1994, I saw Stephen's Quintet very nicely from a dark site with a 14.5-inch Newtonian.  The temperature was in the high 20's and with a brisk wind.  This was the night for me to see the Deer Lick Group (and others) but my hands and feet were freezing and had to leave early.  I sure do wish I'd endured and looked for the Deer Lick galaxies and the others.  And I didn't have my sketch cards.  I was ill prepared.

 

With my 10-inch, I would have been satisfied with only the three galaxies as coined by Tom Lorenzin.  Being galaxies:  NGC 7335, 7336, and 7340.  

 

It was Tom's "1,000+" Star Atlas that I first read about the Deer Lick Group in the early 90's.  Tom and I became friends, as he lived only an hour or so from my house.  He inspired me to attempt too many deep-sky objects to list.  

 

But again, from my suburban backyard....only NGC 7335 was visible, but now I know. 

 

However, maybe next year, I can attempt from a dark-site, and with a larger telescope.  Even making a sketch of the Deer Lick galaxies, beyond the three, and also Stephen's Quintet, and individual galaxies.    

 

 

The following are Tom’s Lorenzin’s descriptive notes from “1000+” based on his October 1983 observing session from the Deerlick Overlook.

 

NGC 7331: 10.4M; 10′ x 2.5′ extent; bright and much elongated edge-on spiral with stellar nucleus; axis oriented NNW-SSE; the Deer Lick group, a very faint triangle of 14+M GALs (N7335,6,40) is a few minutes E and a little N; “STEPHAN’S QUINTET” (soft glow of five very faint and distant GAL’s) is 30′ due S; good supernova prospect.

Edited by Carolina Observer, 01 December 2024 - 03:52 PM.