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Old 20-10-2011, 12:46 PM
Rob_K
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Barnardís Galaxy and more, 19 Oct 2011

Last night was our club observing night at Porepunkah airstrip, NE Vic, and we were greeted with great skies, though not perfect as I suspect thereís still a fair bit of moisture in the air.

Time: 9pm-11pm, Wed 19 Oct 2011 (UT+11)
Location: Porepunkah airstrip, Porepunkah, Vic
Telescope: Tasco 4.5" f8 reflector on Alt-Az mount
EP: 21mm Celestron X-Cel (43x)
Transparency: Good
Seeing: Fair

NGC 6822 (Barnardís Galaxy) in Sagittarius: Iíve observed this dwarf galaxy once before and found the key to finding it was locating a small kite-shaped asterism at its southern end. However, this time I saw the galaxy first and that enabled me to find the asterism! The galaxy appeared large, almond-shaped, and very diffuse and faint, not all that different to similar mottled glow in the surrounding field. It appeared about 15í long and 9í or 10í wide, and a little brighter towards its southern end. Averted vision helped in providing the contrast that made it stand out from the field. One of the other observers had a look and was just able to make out the galaxy, very faintly. We then got one of the Ďcannonsí onto the job (10" dob) at similar power and the galaxy was quite obvious although still very faint. The length visible was about the same as in the 4.5" but the shape appeared a little more rounded (perhaps 11í or 12í wide), and not surprisingly, smoother than in the little scope.

NGC 6818, mag 9.9 planetary nebula in Sagittarius: Had a look while in the vicinity of Barnardís Galaxy. Like all tiny pns, nothing much to see at low powers Ė bright and almost starlike in direct vision, obvious extended source in averted vision. Viewed briefly at higher power in 10", bright roundish source with distinct pale blue tinge to my eyes (even visible in 4.5"). However some others saw it as white.

Comet C/2009 P1 Garradd in Hercules: Had a look at this one early on in lighter skies as it was setting over Mt Buffalo, which towers over the western horizon of the observing field. Not much to see against a crinkly light background, but it appeared as a pale blobby Ďstarí surrounded by low contrast haze. No longer visible from my place because of trees, I think Iíll have to say goodbye to this comet which has put on such a good visual show over recent months! It will be back in southern skies in April next year but considerably dimmer.

Saw lots of other great stuff Ė 47 Tucanae (fabulous, whatever scope), Omega Centauri (sad washed out coccoon, low in light sky), M22 glob cluster in Sgr (brilliant object, great field!), Jupiter & moons low down in poor seeing, naked eye views of the LMC & SMC were stunning, Mira (bright, lovely reddish-orange hue), etc etc etc.

NGC 224 (M31, Andromeda Galaxy): Low object this far south but did have a look at 43x. Only the bright galactic centre stands out, and of course the galaxy extends far outside the FOV. Left my binoculars at home unfortunately. Currently asteroid 372 Palma (mag 11) is crossing in front of the disk of M31 but I hadnít generated charts which would have enabled me to identify it visually. But I did take my (basic) imaging gear out and at the end of the observing session I set it up. Shoot now, identify later! Anyway, here is the (very rough) result:
http://i727.photobucket.com/albums/ww271/Rob_Kau/PalmaM3119Oct2011textc.jpg

All in all a fantastic night Ė good company, great skies, and so much to see!

Cheers -
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Old 20-10-2011, 01:34 PM
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Good write up Rob.

I wonder if Barnard Galaxy's "Ring Nebula" is observable?
http://users.westconnect.com.au/~sjastro/ngc6822nc.html

It could be a target for an OIII filter.

Regards

Steven
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Old 20-10-2011, 02:54 PM
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Paddy (Patrick)
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Great report Rob. And very impressive obs of Barnard's Galaxy in a 4" scope. As always, I dips me lid!
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Old 20-10-2011, 04:11 PM
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barx1963 (Malcolm)
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Barnards is a nice get Rob, I joins Paddy in dipping our lids. It is nearly impossible in the 12" with any light pollution as I still haven't managed it.
Nice image BTW

Malcolm
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Old 21-10-2011, 01:03 AM
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Well done Rob catching the Barnards Galaxy. With large, low sfc brightness galaxies (and nebulosity) like that, the key is dark skies, not aperture.

I can recall observing the Seagull nebula with my 4.5" scope from near Renmark, however at home this is not possible with even my 12"!
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Old 21-10-2011, 01:46 AM
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astroron (Ron)
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Good report Rob, especialy in a 4.5" scope
at least someone is getting some observing in
Steven, the H2 regions in Barnards galaxy are quite hard to discern even in my 16" scope.
I have used both O111 and UHC and high mag but was not able to pull out the ring asa ring but just nebulosity.
Cheers
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Old 21-10-2011, 09:28 AM
Rob_K
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Thanks all. One of those nights when you really feel that astronomy is a truly great hobby!

Quote:
Originally Posted by pgc hunter View Post
With large, low sfc brightness galaxies (and nebulosity) like that, the key is dark skies, not aperture.
How true pgc, dark skies are everything. However, given dark skies, a bit of aperture doesn't hurt! It was good to have the 10" available to check observations. Some time ago we did a similar thing, checking a series of faint globular cluster observations in the 4.5" against a larger scope. Great fun!

Must admit I was a bit surprised how easy B'sG was to pick up. The other time I saw it I had to work for a considerable time to draw it out. It was a few years ago, so maybe I'm getting better at it, or maybe it imprints on your brain. Or maybe both. I suspect the skies were at least as good if not better last time.

Cheers -
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Old 23-10-2011, 08:06 AM
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mental4astro (Alexander)
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I second Ron's sentiments on someone getting some observing time in!

I must admit to not having tried for B'sG. I guess I've been swayed away from trying from what I've read previously instead of just having a shot. Lesson learnt.

Rob, the mind boggles at the thought if you were unleased at the sky with a 16" scope. Or a 30"...
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Old 23-10-2011, 10:37 PM
Rob_K
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Thanks Alex. Hope you can grab some dark sky to see it. Really is amazing to see the large, vague, faint glow looming out of the background and think about what it actually is!

Quote:
Originally Posted by mental4astro View Post
Rob, the mind boggles at the thought if you were unleased at the sky with a 16" scope. Or a 30"...
Not really, suspect I'd lose interest very quickly with carry-out, set-up, cool-down, collimation, storage, blah blah...

Cheers -
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Old 24-10-2011, 10:10 AM
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Paddy (Patrick)
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Quote:
Originally Posted by mental4astro View Post

Rob, the mind boggles at the thought if you were unleased at the sky with a 16" scope. Or a 30"...
The Hubble Space Telescope could be retired and James Webb project scrapped.
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Old 30-10-2011, 05:03 PM
astrospotter (Mark)
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The Ha regions in Barnards Galaxy

sjastro asks: I wonder if Barnard Galaxy's "Ring Nebula" is observable?

Answer: Yes but you gotta work for um. I was unable to see a ring and only detected glow in 18" dob. See below if curious.

From way up north here at +36 or so it is easily possible to right away spot the two Ha regions within the galaxy itself.

What you call the Ring from that picture is far fainter and a heavy duty challenge object (at least from up here where there is a lot of extinction) down to 6822.

That region was a goal for some mag 21.6 type skies for me this last August and here is what I pulled out of it with an 18" f/3.7 scope on a very nice night. For my ORs I measure in terms of field of view and then later transcribe from my sony recorder and put measurements in square brackets.

BarnardsGalaxy: 7/10fov [16'] x 4/10 fov [9'] Unfiltered shows the two northern H2 regions. The H2 region to lower left [W] of the other is brightest of the two unfiltered and both appear to bracket the glow one on either side of the north end of the glow in EW orientation to each other. 5mmNag 389x shows EW elongation of the brighter H2 region west of the other one. Looking for the very dim H2 regions we move co-linear west of the two H2 regions by their spacing to a field star. Now move 1/2 of this length to see the H2 regions. These are very dark targets that only present themselves in strained averted over 50% of the time that are closely spaced. Both Kevin and MarkW saw these as well.


Mark
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Old 03-11-2011, 09:42 AM
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madbadgalaxyman (Robert)
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A good and accurate observation of Barnard's Galaxy, Rob.

I find that galaxies that are bright enough to register in binoculars (50-80mm aperture), but which have an extremely low surface brightness, such as N6822 and Messier 33, often show very well in very low power instruments, even if the instruments which are used are of small aperture.

The additional contrast of using two eyes with binoculars, and the low power of binoculars, seems to do the trick on NGC 6822 and M33; the contrast of the object against the field is actually greater - at least as far as it looks to my own eyes - than it is in a monocular telescopic view at higher magnification.

As another example, there is one small portion of Barnards Loop that I have found is a binocular object; but I doubt if you would notice the contrast between the nebulosity and the field at a normal telescopic magnification!
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