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TAC Visual / Re: Experienced Eclipse Chasers. Your input please.
« Last post by mccarthymark on August 02, 2017, 04:31:07 PM »
I'm no expert, but I thought this was a good description of what will happen

http://www.eclipse2017.org/2017/what_you_see.htm
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TAC Visual / Experienced Eclipse Chasers. Your input please.
« Last post by Mark on August 02, 2017, 08:54:51 AM »
I know there are many experienced eclipse chasers here.  This month's will be my, and undoubtedly others, first.

How about posting what to watch for, and how?  Visual stuff.  I recall listening to a recording made by someone experienced, and they were calling out the various events as each approached.

I'd like to have such a list, as the group I'm going with are not only eclipse newbies, but total astronomy noobs, far as I can tell.

Thanks for any and all suggestions.

Mark
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Observing Reports / Re: Globular Cluster hunting -- in Barnard's Galaxy!
« Last post by sgottlieb on July 29, 2017, 02:37:12 PM »
Thanks Mark and Marko for the comments and posting the finder chart.  SC 6 is already on my observing list as it's only a 1/2 magnitude fainter than SC 7, but I didn't take a look at Grandview.  Maybe next month.  For the record, here are the coordinates of these two exotic objects.

SC 6   19 45 37.0 -14 41 10.8
SC 7   19 46 00.7 -14 32 35.0

A 2005 study titled "The Globular Cluster System of NGC 6822" (https://arxiv.org/pdf/1506.00951.pdf) gives the following magnitudes (rounded to nearest tenth):

SC 6  15.4V
SC 7  14.8V

Let us know if anyone gives these a try.

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Observing Reports / Re: Globular Cluster hunting -- in Barnard's Galaxy!
« Last post by Marko on July 29, 2017, 01:57:58 PM »
From the paper i take it Sc6 and Sc7 are around mag 15 and thus doable with very steady skies and 18" scope.

Nice tip for a mini-project.  I enjoy poking about for extra galactic globs in nearby galaxies.

Another link that I found more accessable to that paper was seen at https://www.researchgate.net/profile/Avon_Huxor/publication/233427060_Three_newly_discovered_globular_clusters_in_NGC_6822/links/541032590cf2df04e75b897b/Three-newly-discovered-globular-clusters-in-NGC-6822.pdf

I also attach a quick finder 1-page summary just made for my usage at a later date.
Both Sc6 and Sc7 seem to show up nicely in MegaStar with DSS so other DSS sources should show them fine.

Thanks,
Marko
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Observing Reports / Re: Globular Cluster hunting -- in Barnard's Galaxy!
« Last post by Mark on July 28, 2017, 10:27:56 PM »
Great observation Steve.  Reminds me of how surprisingly easy it was seeing that new glob near B86 a few years ago.  Interesting what can be seen.  With I'd been there!
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Observing Reports / Globular Cluster hunting -- in Barnard's Galaxy!
« Last post by sgottlieb on July 28, 2017, 06:01:55 PM »
For the July new moon I observed for 4 nights in the White Mountains above Bishop (Grandview Campground at 8500 ft), just below the Ancient Bristlecone Pine Forest.  Our group included Paul and Debbie Alsing, Kemer Thomson, John Hoey (all from the San Diego area), Jimi and Connie Lowrey (from west Texas but drove from Florida) and bay area locals Carter Scholz and Rick Linden.  The weather turned out great and the Detwiler fire southwest of Yosemite didn't impact us, though I drove through the smoke in Yosemite to reach the site.  SQM readings were generally in the 21.6-21.8 range, though occasionally below 21.5.  The largest scope was Rick's 32", which nearly dwarfed my 24" Starstructure.

Instead of posting a long list of observations (I logged 125 objects), I'll mention just one -- a Sagittarius globular that actually resides in Barnard's Galaxy (NGC 6822).  Edwin Hubble was the first to investigate Barnard's Galaxy in detail in 1925 (http://cdsads.u-strasbg.fr/full/1925ApJ....62..409H).  His study included a table of 10 nebulous objects within Barnard's Galaxy.  Most of these turned out to be HII regions (including 2 great visual targets), but Hubble VII turned out to be the first confirmed ancient globular in this galaxy.  The location, though, creates a problem -- its a tiny 16th magnitude speck superimposed on the glow of the galaxy and a very nasty visual target.  I was successful observing it twice from GSSP back in 2010 with my 18", though it was quite challenging (barely non stellar and lost in a maze of other dim stars within the galaxy).  I figured that was the last GC I'd see in Barnard's Galaxy

Four new globular discoveries in this dwarf galaxy were announced in 2011 but these seemed too faint for visual targets.  Then in 2013 three more were identified (so the current total is 8 ) and globular #7 (coincidentally the same number as Hubble's object) seemed a reasonable target for my 24".  When I added it to my observing list, I had no idea what to expect as I've never read of amateur observations of these globulars. You can read the discovery paper at http://adsabs.harvard.edu/abs/2013MNRAS.429.1039H, where it's called SC 7 (Star Cluster 7)

SC 7 is in the outskirts of Barnard's Galaxy, 22' NE of the center of the galaxy and well outside the visual extent -- that makes identification much easier!  Once the general field was centered using the 6mm Delos (375x), both Jimi Lowrey and I were surprised to quickly notice a non-stellar glow without first examining an image of the galaxy.  SC 7 was faint in my 24-inch, but clearly non-stellar, roughly 6"-8" diameter and 15-16th magnitude.  The globular could be held steadily when we backed the magnification down to 282x and possibly had a brighter stellar nucleus.

If you're curious about the distance, Barnard's Galaxy is ~1.6 million light years away.  For comparison, the most distant Milky Way globulars are 300 to 400,000 l.y. away, so this one is at least 4 times that distance!  I believe an 18" scope should catch this object from a dark site, if you know the precise location.

-- Steve 


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Observing Reports / Re: Speaking of subtle...
« Last post by sgottlieb on July 27, 2017, 10:22:09 PM »
Great set of targets, Mark!!

As far as GN 18.32.5 = PNG 27.0 +1.5, it's definitely a planetary neb and not a reflection nebula -- SIMBAD is wrong, wrong, wrong.

Check out this page from the MASH catalogue:  http://vizier.cfa.harvard.edu/viz-bin/vizExec/.show?V/127A&G027.0%2b01.5.  Perhaps I mentioned this one to you before?

I made two observations 9 years back with my 18" ---  I noted the planetary wasn't symmetric around the central star (as you also commented).

18" (7/31/08 and 8/1/08): At 175x unfiltered a mag 13 star was visible and a small ill-defined halo was highly suspected surrounding the star knowing the exact location.  Adding an OIII filter, the halo brightened nicely and the edge sharpened to a 20" disc.  The involved star appeared offset to the north side.

For comparison, here are a few more observations ---

Alvin Huey (22" @184, 255 and 328x): Considerably faint round glow with defined edge with a very bright central star.   Estimated magnitude of the central star is about 11.5.  Not visible without filter.  Ultrablock brings it out pretty well and a similar response with O-III filter.  About 0.5' across.

Kent Wallace (20" @134X and 169X): could see the star superimposed on the northern side of the PN as shown in the SuperCOSMOS blue image. Using the O-III filter and averted vision, a blob forms on the southern side of the star. Good response to the O-III filter. Fair response to the UHC filter. No response to the H-Beta filter. The image is best at 169X. At 254X, the image isn't very good. Identified the field in the AP finder chart. This is a first known visual sighting.

Kent Blackwell (25"): Easy to find because of its involvement with an 11.4 magnitude star.   Even in bright moonlight I could still see it. Once I sighted the nebulosity with the filter I could see it without a filter. It responds so well to the OIII the nebula nearly outshines the involved 11.4 magnitude star.

-- Steve



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Observing Reports / Re: Speaking of subtle...
« Last post by DDK on July 27, 2017, 01:41:06 PM »
Phoo, McCarthy et al, I didn't pass along the link for that list. It's still archived at
http://old.observers.org/observing/eyecandy/

One of the most fun observing lists around, on purpose! Made with the same philosophy as Steve's DeepMap - these better look good.
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Observing Reports / Re: Speaking of subtle...
« Last post by mccarthymark on July 27, 2017, 12:12:46 PM »
I guess I have gone off the "deep" end, haven't I...    ;)
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