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Old 31-07-2014, 07:31 PM
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mental4astro (Alexander)
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Polarissima Australis - neighbours close to it?

Hi all,

After three years, I finally got to sketch this 14th magnitude faint fuzzy, Polarissima Australis, NGC 2573, the closest catalogued object to the South Celestial Pole. I've got a write-up of this sketch in the DSO sketching sticky.

But this thread is not about Polarissima Australis. It is about a curious thing I noticed through the eyepiece with my 17.5" dob. While observing NGC 2573, I noticed two other even fainter faint fuzzies very close to PA. Not just my own observation, but other people at Astrofest also noticed these two faint ghosts. The one to the left of PA being a little brighter than the one on the right, and both being really faint - suck-your-eyeballs-out faint!

Thing is, I don't have any atlases or the such to give me an idea of what they are.

I've attached an image of my sketch where these two puffs can be seen just above and on either side of PA.

Anyone have any clue as to what these two items could be please?
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Old 01-08-2014, 06:54 PM
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hickny (Peter)
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Does this help?
http://www.absoluteaxarquia.com/nightsky/octans.html
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Old 01-08-2014, 07:17 PM
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mithrandir (Andrew)
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Alex, what's the FOV of your sketch? Which way are N and E?

The one on the left could be PGC215090, and the two on the right NGC2753A and NGC2753B. Those two are very close together - ~80 arcsec.

If the image is left/right inverted the spacing would better match the positions I see in CdC
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Old 01-08-2014, 07:23 PM
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hickny (Peter)
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Alex,
Try this link...
http://www.docdb.net/search_constellation.php
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Old 01-08-2014, 07:25 PM
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hickny (Peter)
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and this one...
http://www.glitteringlights.com/Imag...ae/i-KtF89sj/A
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Old 01-08-2014, 08:21 PM
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mental4astro (Alexander)
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Quote:
Originally Posted by mithrandir View Post
Alex, what's the FOV of your sketch? Which way are N and E?

The one on the left could be PGC215090, and the two on the right NGC2753A and NGC2753B. Those two are very close together - ~80 arcsec.

If the image is left/right inverted the spacing would better match the positions I see in CdC
I hoped this could prove to be a bit of a task, . I'm glad it is,

Andrew, the FOV of the sketch is approx 0.35deg, North is to the top, East to the right.

The position of the fuzz on the right is less accurate as it was a real struggle to see and note accurately. Polarissima was difficult for most people to spot, the other two fuzzies were seen by two or three they were so faint. By the description you give, you could well have pinned the items.

Peter, thank you for the links. The second one in particular is a cracker source for me. I might have to put my sketch of PA in as an image...
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Old 01-08-2014, 08:22 PM
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Hi Alex,

Your query rather intrigued me.

Here is a screen clip from wikisky roughly the FOV of your diagram. I have added the magnitudes of some of the stars.
The approximate location of your two "puffs" are indicated by the asterisks. PGC 215090 (mag 16) is too far away. It is unlikely you would see it in your scope anyway.

Nothing much appears where the two asterisks are.
The images on wikisky would show objects much fainter than what you could eyeball in your telescope even if it is a 17.5 inch scope.

Discounting reflections in the eyepiece, it is possible that your two puffs may be small regions of slightly higher star density. These can give the illusion of nebulosity.

Regards, Rob
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Old 01-08-2014, 08:56 PM
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mental4astro (Alexander)
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Rob, thanks mate! Looks like the mystery has been solved - the cumulative glow of individually invisible stars. This is what we pretty much see with the background glow of the Milky Way, and here it is on a much smaller scale.

Thanks mate,

I hope this has also served to prick up some interest in this very little observed/investigated galaxy. It has such a gorgeous name it really deserves more attention, especially for the challenge it also presents,
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Old 16-04-2019, 09:19 PM
A1 (Jason)
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Thank you Alex and everyone,

I've set a goal to spot NGC 2573 with my 12 inch Dob and all your info is very helpful.

Regards, Jason
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Old 17-04-2019, 02:30 AM
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Hi Alex,

I think you would find Skymap very useful:

http://www.sky-map.org/

At the positions you have drawn (or within 8 arc-minutes) there are no apparent galaxies or other nebulous objects (down to about 18th magnitude at least), so this would seem to be, as you have noted a spurious observation. That's not a criticism, in any way, our eyes and imaginations sometimes do play tricks on us at the edge of the envelope -- even for experienced telescope users. We all sometimes make mistakes or incorrect assumptions -- that's human nature.

There's no better (or more curious) case of this than Baxendell's "unphotographable" nebula -- NGC 7088. A non-existent "nebula" near M2 in Aquarius that was originally reported by Baxendell in 1880 and "observed"
by Dreyer (1885, 10-inch refractor)(Included in the NGC as NGC 7088), Bigourdan (1897, 12-inch refractor), Hagen (1915 and 1917, 16-inch refractor), Wolf (1927, 6-inch refractor), O'Connor (1929, 15-inch refractor), Becker (1930, 12-inch refractor) and Lehner (1930, 4-inch refractor). But never showed up on any photographs of the area -- no matter how deep the image.

It was later concluded that it must have been some sort of strange internal reflection caused by nearby M2.

Curiouser and curiouser, in the 1980s it was reported again by a few prominent U.S based Deep Sky Observers (it was still being marked on maps even in the 80s and 90s) and described in near identical terms to Baxendell's initial observations. I remember well the ferocious storm that erupted over claim and counter claim that is was or wasn't real (and who was lying and who wasn't) -- unedifying.

Some claim it might be a bit of IFN (integrated flux nebulosity) at high galactic latitude but even so I does not **ever** show up on photos no matter how deep. It must be spurious -- there is no other explanation.

I have spent a total of about 30 minutes using both 10 and 18" 'scopes checking the alleged location and for me there was nothing at all that could be described in any way as "nebulous" in the area. There isn't even any field irregularities (a clump of faint stars or an area where there is an over-abundance) nil, zip, nada. Deep images show the same.

That's a quite of list of famous and otherwise credible, capable but clearly mistaken visual observers who said they saw it --Dreyer, Bigourdan Hagen, Wolf, O'Connor, Becker & Lehner!

As for the U.S observers in the 1980s, I won't name names (until they're all dead!)

Best,

L.
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Old 17-04-2019, 02:09 PM
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mental4astro (Alexander)
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Hi Les,

Mate, no offense taken I understand exactly what you are saying.

What caught me by surprise was I had seen Polarissima Australis on other occasions, and I had not seen that other faint fuzzy. This particular observation and sketch was done during the Qld Astrofest. I had asked people with various astro apps to look up "PA" to try to identify this new faint fuzzy, and nothing was to be found.

It was only after I got back home two things:

1, Check this sighting through another big dob - there were plenty there.
2, That it could have been an unreported comet - it had every appearance of being a comet, being round, diffuse and no immediate nucleus. But without being aware of this possibility, and not being aware of the verification process for a positive identification, nothing more I can do Oh well... We had seen four other comets that night.

If it was a new comet, it slipped through through my eyepiece...

On the plus side, i have become acquainted with the verification process laid out by the International Astronomical Union.

Alex.
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