Virgo Galaxy Cluster - April 2008

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

Well, Pete, that is a sweet image! I especially like PGC 40659 hiding under M86! That is cool.

That hexagon you've got there looks an awful lot like a shutter iris...???

Well, so far, Pete is leading the challenge. I sure hope this falls into different divisions also, or this is over before it begins... :?
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
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"He numbers all the stars, and calls each one by name." Ps 147:4
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Pete
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Artifact problem solved!

Unread post by Pete »

Dean at Starizona got back to me, guessing that that 6-sided figure was a digital artifact and not associated with the Hyperstar system.
Checking things out, he was right! The artifact was not present in the original single unstacked images nor was it present in the
Envisage stacked image. The six sided figure only occurred when the images were stacked with Registax!

Here's a reworked reprocessed view of M86 (L) and M84 (R), this time with N up and E to the left as is conventional:

Image

It's not quite as pretty with the grain showing a bit, but it sure does show a slew of galaxies. Now if I can only figure out how to get
rid of the grain and not the detail......

Pete
Pete P.
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WCGucfa
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Unread post by WCGucfa »

Hey Pete,

I just got a chance to see your M84/86 image. WOW! You've come a long way baby!!!

Bill

P.S. Your six-sided "thing" looks like a camera iris reflection/flare, too faint until you post-processed. It's elongated due to the angle from whatever object caused it. What the heck am I talking about, not even knowing the construction of your camera!? :shock: Glad Starizona had their own story. :wink:

BG
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Bruce D
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Unread post by Bruce D »

Nice Pete, now THATS a galaxy cluster :!:
Bruce D
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Pete
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Unread post by Pete »

WCGucfa wrote:Your six-sided "thing" looks like a camera iris reflection/flare, too faint until you post-processed. It's elongated due to the angle from whatever object caused it. BG
That was my initial thought too, Bill. After all I did get that strange reflection in the system when imaging the Flame. But this "flare" isn't present in the raw images when I post process them individually. Definately a digital artifact from Registax.

Pete
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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
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Total.Sol.Eclipse,7/10/72 from Nova Scotia.Annular Sol. Eclipse '94,
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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
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