Virgo Galaxy Cluster - April 2008

General astronomy-related discussion (publicly viewable)
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WCGucfa
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Unread post by WCGucfa »

Very good mystery solve Pete and much easier to remedy I'm sure!

Bill
Comets:40, Best Meteor shwr: Leonids '01, Best Aurora:Oct. '03.
Total.Sol.Eclipse,7/10/72 from Nova Scotia.Annular Sol. Eclipse '94,
Trans.of Venus 2004&2012.,ShoeLevy crash into Jupiter '94.
4/25/66 fireball-9 mag.,SN2011fe,N2012aw,DelphN2013.
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Rotorhead
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Unread post by Rotorhead »

I wonder if it has something to do with the stacking process as the program tries to align guide stars.... It is such a precise artifact, but I do remember how the Flame photo also baffled us. That time we suspected the brightness of the nebula, but this time it is dim galaxies.
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
________
"He numbers all the stars, and calls each one by name." Ps 147:4
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WCGucfa
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Unread post by WCGucfa »

Yes Bob, it is a precise artifact. That fact is keeping me supicious. I would continue to argue if I knew more about the mechanics (shape) of the iris. Show me an aperture that isn't hexoganal anywhere in the system and I'll pack up and leave. :wink:

Bill
Comets:40, Best Meteor shwr: Leonids '01, Best Aurora:Oct. '03.
Total.Sol.Eclipse,7/10/72 from Nova Scotia.Annular Sol. Eclipse '94,
Trans.of Venus 2004&2012.,ShoeLevy crash into Jupiter '94.
4/25/66 fireball-9 mag.,SN2011fe,N2012aw,DelphN2013.
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BobSikes
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Great Shots

Unread post by BobSikes »

Nice image Pete!
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Pete
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Unread post by Pete »

There's no iris at all Bill. But I did use about 9 registration points when I alligned and stacked in Registax. All I know is the Meade single point stacking didn't have the flaw.

Pete
Pete P.
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WCGucfa
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Unread post by WCGucfa »

Thanks for the info Pete. Now I can stop thinking "iris" and get on with my life!
Six points doesn't equal nine points so the "why" of the artifact shape still baffles me. But does it really matter as long as you can eliminate it? No!
I had a book once that tried to solve all image/camera problems with the use of photographic examples - it was excellent. Digital imaging has taken us into a whole new world. :shock:

Bill
Comets:40, Best Meteor shwr: Leonids '01, Best Aurora:Oct. '03.
Total.Sol.Eclipse,7/10/72 from Nova Scotia.Annular Sol. Eclipse '94,
Trans.of Venus 2004&2012.,ShoeLevy crash into Jupiter '94.
4/25/66 fireball-9 mag.,SN2011fe,N2012aw,DelphN2013.
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Rotorhead
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Unread post by Rotorhead »

Well, now that we can stop worrying about irises, how about the challenge? Last night at Horseneck Beach, I was able to gather four galaxies in one view, visually. M84/86 and the background galaxies which appeared to be NGC 4402 and 4387. There was a possible fifth, but with greatly averted vision and I could not identify a shape for it, so I don't know if it was real.

When are we going to get a really clear night???? :?
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
________
"He numbers all the stars, and calls each one by name." Ps 147:4
Bruce D
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Unread post by Bruce D »

Bob M wrote
When are we going to get a really clear night????
When Omega Centauri is no longer peeking over the horizon? :!:
Bruce D
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Rotorhead
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Unread post by Rotorhead »

Quite probably. :( I'm off to write an observing report on my attempt at Omega, posted elsewhere.
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
________
"He numbers all the stars, and calls each one by name." Ps 147:4
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