NGC5128 Centaurus A

[cometcatcher (Kevin)]

I only get a few days per year here in the tropics where it stays clear enough to barely get enough data for the average galaxy. This would be my deepest Cent A to date, the stars top out at about magnitude 18. While it's clear and cool, the air is turbulent though so not as sharp as it could be.

Details: 233 x 1 minute subs, just 7 minutes short of 4 hours, Skywatcher ED100 at prime focus F9, Pentax K-5, HEQ5 Pro unguided, poked out the kitchen window.

I would have gained several more subs if I didn't fall asleep in the middle of it. Also lost a few subs due to vibration from my cats Rigel and Orion playing around the tripod. But these things happen lol.

Bigger ----> http://astrob.in/105211/0/

[jsmoraes (Jorge)]

I saw in astrobin full resolution and it is very nice. Many details and colors are very well. I suppose it was unguiding, too. But the shape of stars are well. At this time some stars have a blue ring around: refraction or chroma distortion ? I have had some ones alike, but I reckon they were by humidity of atmosphere (refraction)

I love this galaxy. It remembers the submarine of Twenty Thousand Leagues Under the Sea from Julius Vernes. Well, no problem ! Many people see many things that I never could see or imagine with stars and named them as constellation ... as nebula ...

[alpal]

Nicely processed & a good example of what can be achieved with
an extreme number of sub frames.

[Eden (Brett)]

...poked out the kitchen window.

As all good telescopes should be! Nice job Kevin, well done.

[RickS (Rick)]

A great result, Kevin!

[cometcatcher (Kevin)]

Thanks all.

Jorge, yeah there's CA in the system somewhere. I used a field flattener because there is a hot spot at the center and it smooths it out. But it may be introducing CA. I'll do some tests without it and see if it improves.

[Retrograde (Pete)]

Wow that's really good - especially from an ED100!

[cometcatcher (Kevin)]

Thanks Pete. Well it's no Tak, but it works. Looks like the faults start to show on the really big blowups, so I'll have to keep them smaller.

[cometcatcher (Kevin)]

Originally Posted by jsmoraes

... At this time some stars have a blue ring around: refraction or chroma distortion ?...

Did a test Jorge to see where the CA is coming from. This is straight through, no lenses other than the main objective and this is where the CA is coming from. So my ED100 has some CA. I'm not really surprised, it's just a doublet with one ED element. It's not noticeable visually, only when zoomed in on a photo. This is a 200% enlargement from the 16mp sensor.

[Dealy (Kev)]

Great shot Kev

[cometcatcher (Kevin)]

Thanks Kev.

[TimberLand (Justin)]

For me the jury is still out on which is best high subs or long exposures, and this is a tick for lots of subs.

Well done.

[alpal]

Originally Posted by TimberLand

For me the jury is still out on which is best high subs or long exposures, and this is a tick for lots of subs.

Well done.

The best DSLR pics I've seen always have 100s of sub frames.

[cometcatcher (Kevin)]

Everything I've read say that longer subs are better, but with an uncooled DSLR, thermal noise then becomes a problem. See my thread here. http://www.iceinspace.com.au/forum/s...d.php?t=122602

[astronobob (Bob)]

Im impressed with the amount of extended galaxy halo/glow for 1min subs, well done and some great deatails there aswell Kevin
Top stuff !

[cometcatcher (Kevin)]

Thanks Bob. One draw back of many subs is the hard drive is filling up very quickly...