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Leo 1 & Hickson 50 challenge

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#1 nytecam

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Posted 21 February 2014 - 03:42 PM

Last night I returned after a two year break to remote Hickson 50 gxy-gp in Uma nr M97 and 20' N in the glare of Regulus in Leo1 as below eg challenging visual targets :o

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#2 nytecam

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Posted 21 February 2014 - 03:44 PM

Hickson 50 = 5 gx group UMa - what do you make of them and Leo 1?

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#3 Astrojensen

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Posted 21 February 2014 - 04:46 PM

I've tried Leo 1, but never seen it so far. Hickson 50 is beyond the grasp of any of my current scopes, at least from my observing location. Maybe from Mauna Kea, who knows. ;)


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#4 Sasa

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Posted 21 February 2014 - 05:05 PM

Thomas, it should be relatively easy in your 150mm f/8 refractor. When I was testing and playing with 150mm f/6 refractor that my friend just acquired, even complete novices were able to glimpse it. Before that, I could detect it also in 100mm refractor. All it requires is to run on good night.

#5 David Knisely

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Posted 21 February 2014 - 05:08 PM

I have seen Leo-1 many times in my 10 inch as long as the sky is reasonably transparent and I keep Regulus out of the field of view. It is dim and large but I don't consider it terribly difficult once you know what you are looking for. As for Hickson 50, I doubt I would ever pick up this group visually in my 14 inch, as all the galaxies in it are 17th magnitude and fainter. Clear skies to you.

#6 Astrojensen

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Posted 21 February 2014 - 05:52 PM

Thomas, it should be relatively easy in your 150mm f/8 refractor. When I was testing and playing with 150mm f/6 refractor that my friend just acquired, even complete novices were able to glimpse it. Before that, I could detect it also in 100mm refractor. All it requires is to run on good night.



Getting a good night is precisely the problem. Spring around here usually gives us very damp nights with lots and lots of haze, which will completely wash out Leo 1. On the few very good nights during this season we've had, I've simply forgot looking for it.

Oddly, the somewhat hazy nights doesn't seem to harm other galaxies too much, as long as they're not near any bright stars. Or maybe I'm just so used to humid nights, that I have nearly forgot what a really clear night looks like. I do get one or two each year, if I'm lucky.

Frankly, I have a feeling, that that's the case.


Clear skies!
Thomas, Denmark

#7 Bill Weir

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Posted 22 February 2014 - 12:41 AM

Fabulous. Your images show so well how people can expect to see objects visually.

Once on a perfect winter night I was able to make out Leo 1 with my 6" dob from my back yard. In my opinion observing this object depends/relies on good transparency.

Hickson 50 took a bit more. The first time I located this group was using the 25" eq mounted newtonian at a school observatory a few km down the road from my place. Since then I've seen it a few times with my 20" from my driveway. This an object where visually at least aperture rules.

Bill

#8 sgottlieb

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Posted 26 February 2014 - 11:36 AM

Bill, I'm curious if you were able to see more than a single object (HCG 50A)? That's all I've managed in my 24", but I thought I'd mention an experience I had with HCG 50.

The first time I looked for HCG 50, I found a single very dim object at the right position that I assumed was HCG 50A. It seemed virtually stellar, but I had seen the group resolved in a 48" in good conditions and I knew they were very tiny.

On a later observation, though, at higher power (450x), I realized that the object I took for HCG 50A previously was a mag 16-16.5 star shown in Maurice's image just to the lower right of the galaxy group! When HCG 50A "popped", it was clearly fainter than that star and only visible intermittently.

#9 Bill Barlow

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Posted 26 February 2014 - 08:21 PM

Very nice image of HCG 50. Do you know how far from Earth this group is? The farthest Hickson group that I have seen visually in my C14 from a yellow zone is Hickson 94 while some of the faintest groups were Hickson 57 and 56.

Bill

#10 Bill Weir

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Posted 26 February 2014 - 11:32 PM

Steve your observation mimics mine in a way. I was ready for that star to confuse me though as I had an image in hand while standing at the top of the ladder while the f/5 25" was pointed way up. It's so much nicer with my f/3.3 20" to be standing on the ground while objects are at similar locations in the sky. As you say, only one galaxy was visible in the group. With the 25" I would have been using a 7.5mm eyepiece for approx. 420X and with the 20" a 4mm for 456X.

Several years back I was at the 90th birthday party for the Plaskett Telescope here in Victoria where Dr. Paul Hickson served us the cake http://rascvic.zenfo...942ac#h105942ac I had a nice conversation with him and thanked him for presenting us visual observers with such a wonderful challenge. His comment was, "thanks and they are also so pretty to look at."

Bill

#11 sgottlieb

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Posted 26 February 2014 - 11:38 PM

Very nice image of HCG 50. Do you know how far from Earth this group is? The farthest Hickson group that I have seen visually in my C14 from a yellow zone is Hickson 94 while some of the faintest groups were Hickson 57 and 56.

Bill


Bill, HCG 50 is a very distant group with a redshift of z = .139, corresponding to a light-travel time of ~1.8 billion years. That's 80% more distant than the Corona Borealis cluster!

#12 hbanich

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Posted 27 February 2014 - 12:26 AM

I've seen two members of Hickson 50 with my 28 inch and they were definitely much fainter than the 16-ish magnitude foreground star. I didn't know they were that far away Steve, thanks for the info, and the comparison to the Corona Borealis Cluster is fantastic.

#13 sgottlieb

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Posted 27 February 2014 - 10:53 AM

Howard, for comparison here's my notes with Jimi's 48". Something to look forward to!

48" (4/15/10): Four members of HCG 50 = Shkh 5 from mag 18.7(B) to 19.6(B) were visible at 623x and 701x. Three members were seen immediately at 623x and the 4th picked up and sketched at 701x (without prior reference to an image). All 4 members were very small (at most 10" diameter) and crammed into a region measuring 40"x24".

50A: at 700x appeared very faint, very small, 10" diameter. Situated 20" NE of a mag 16 star.

50B: the "B" component of HCG 50 lies 16" E of 50A (closest member) and 35" NE of a mag 16 star. At 700x, it appeared very faint and small, roundish and a little fainter than 50A. No elongation was noted.

50C: the "C" component lies 27" N of a mag 16 star and 25" NW of 50A. This was a difficult object at 700x (faintest of 4) with a low surface brightness and less than ~6" diameter.

50D: third brightest of 4 viewed in HCG 50. At 700x it appeared extremely faint and small, ~6" diameter. Forms the northern vertex of an equilateral triangle with 50A (22" S) and 50C (24" SW).

#14 nytecam

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Posted 27 February 2014 - 02:10 PM

Thanks Steve and all the contributors to this post - some wonderous views recorded there - many thanks :bow:

My montage of M97 PN + Hickson 50 field here - click image for full size. Wow @ 1.8 BLY range :grin:

#15 Bill Barlow

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Posted 27 February 2014 - 07:23 PM

Thanks for the information on HCG 50 distance from Earth. Wow, that's really out there a ways! From the photographs Nytecam took, these objects are tiny compared to the stars in the line of sight. I have found that when using my C14 to try and find these Hickson groups, anything fainter than surface brightness Mag. 15 will be too faint for me to see it visually given I observe in a yellow zone. Copeland's Septet/HCG 57 is usually a challenge for me to see all 7 members.

Bill

#16 Ptarmigan

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Posted 27 March 2014 - 10:17 PM

Hickson 50 is very faint. Faintest Hickson Compact Galaxy Group. Leo 1 is hard to see due to being near Regulus.






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