Omega Centauri

[Tom Davis]

Here is one more image, if I may. My goal in this image was to capture the halo of faint stars surrounding the main body of the cluster.

http://www.tvdavisastropics.com/astroimages-1_000074.htm

There are a lot of stars there!

Tom

[renormalised]

Damn fine shot, Tom. Plus a few galaxies thrown in, too boot!!!!.

10 Million stars in the cluster, give or take a few:)

[Kevnool]

Another grand image Tom.
See the bonus galaxies in there as well.
Great work.....cheers Kev.

[Tilt]

Excellent image Tom, so many stars!

Michael

[gregbradley]

Hi Tom,

I like it but it seems a tad too blue to me. You certainly got all the stars, resolved to the core etc. I know it has a blue look to it but perhaps not that much.

I hope you make an excellent recovery from your surgery.

Greg.

[Jen]

:thumbsup::thumbsup: Dam Tom what ya been doing storing all these pics away for a rainy day :lol::lol: then popping them all out one after another :P
nice work cheers :thumbsup:

[Jeff]

Wow Tom, the star field is absolutely amazing and testament to what must be some outstanding equipment and well honed techniques.

I especially like the enhanced star colours and 3 dimensional impact from the variety of star sizes. And the galaxies ....

Jeff

[Hagar]

Certainly is a lot of stars in the outer area. I love the spread of colour in your stars. Beautifully processed and such fine pin point stars.

[Tom Davis]

Thanks Greg. I too thought that it was a tad too blue but when I looked again at my G2V data and histogram it looked correct. So, for better or worse, I just left it. Maybe I'll tone it down some though.

Sorry to hear about your AP adapter. Yes, FlI has a pretty shallow thread.

Tom

[atalas]

Nice and different Tom.

[gregbradley]

Colour is often the hard part of the image so it could simply be my preference. It definitely has a lot of blue stars in it for sure.

How do you do your G2V callibration?

Greg.

[Tom Davis]

I follow Don's method. It's simple.

http://www.astrodon.com/Orphan/g2v_tutorial/

Tom

[gregbradley]

Thanks Tom,

I feel like I am getting tuition from a master craftsman!

Cheers,

Greg.

[TrevorW]

Someone turn out the lights:cool2:

[iceman]

Congrats on a beautiful image, and congrats on APOD today!

Well done!

[Tom Davis]

Thanks Mike.

Tom

[Jay-qu]

You have some stunning APOD's Tom, well done :)

[gregbradley]

That looks good Tom.

Did you also bring out that dust in the bottom right side?
I notice it shows when the mouse cursor is on the page and disappears when the cursor
is off the page. Is that intentional or an artifact?
I can't believe you found dust in Omega Centauri:eyepop:

How do you get the dust to show up so well? Careful curves for that
part of the curve where the dust is (down low)?

Greg.

[Tom Davis]

Hi Greg,

The dust is real but very very faint. I brought it out with curves but only made it stand out with the mouse-over. I am surprised that dust was in the region as well. Maybe it is flux nebulosity. I'll have to check.

Tom

[astroron]

Hi Tom, Stunning image.
Is that green dot at the six o-clock position an artifact?

[pgc hunter]

spectacular shot!

[jase]

Great work Tom. The crop is a real cracker. Thanks for sharing.

[Bloodbean]

Great image Tom! I just spent a few minutes staring at the image looking around at everything. Well done keep them coming..

Troy

[strongmanmike]

First of all a spectacular image Tom :clap:

It seems now that an image is not truly deep if there isn't "Galactic Cirrus" or other faint dust showing (You should know Mr Dust Pan :P). Funny how things progress in any endeavour or sport etc. Another good example is the Dumbell Nebula, if the outer radial Ha sprays aren't showing then it just ain't deep enough, 20yrs ago amateurs didn't even know that nebulosity was there :eyepop:. In a talk he gave to the Ice in Space Astro Camp back in 2007, David Malin issued a challenge to see if an amateur could reveal the very faint GC around Cen A and this was what propmpted my efforts to capture it but I am sure this nebulosity will soon be commonly seen in images of Cen A before too long.

It is very interesting to compare your relative marathon (for a globular image) to my almost snap shot - at first there appears to be little difference in size but once you reference some outliers in both images the extent you have revealed is quite large.

Yep as mentioned, that dust is more commonly known as Galactic Cirrus and has been for many years in fact. David Malin imaged heaps of GC a generation ago. "Integrated Flux" is a term more recently coined by some people who claim they were the first to showcase it as a mixture of emission and reflection, so the term seems to have stuck, particularly in the US.

Here is Our own Steve Crouchs effort from 2006 showing some GC near Omega Cen note the short exposure times...F2.8 helped of course:
http://members.pcug.org.au/~stevec/NGC5139_STL11K_E180.htm

[astroron]

Hi Mike is there a link to your Cent A image?

[strongmanmike]

Your kidding right..? I'll be lynched if I post a link to another Cen A :scared:


...?...ok...carefully looking out fropm under the blankets...

http://www.pbase.com/strongmanmike2002/image/97061387/original

and here is a mozaic of three different results from the same data set:

http://www.pbase.com/strongmanmike2002/image/109443142/original

ah what the heck... here is the whole bleedin album :whistle:

http://www.pbase.com/strongmanmike2002/centaurus_a

I'm running for cover now :hi:

Mike

[astroron]

Brilliant:thumbsup: you can come out now:D

[Tom Davis]

Yep, it's there. Great to know!

Thanks Mike!

Tom

[astroron]

:hi:Tom, as I asked in an earlyer post, is that green dot at six oclock position an artifact?
cheers :thumbsup:

[Tom Davis]

I can't see it. Can you point it out on my image and I'll look at the full frame to let you know what it is.

Tom

[astroron]

Thanks Tom:)
Sorry to desecrate your image:(but here goes:)
It is on both the cropped and uncropped images:thumbsup:

[Tom Davis]

I don't know. It looks like an star with very green bias. Strange though, as it is the only one. What do you think? I've seen a few small planetary nebulae that come off with a green bias but this is green! Great pick up!!

Tom

[gregbradley]

That's just an artifact. You got a cosmic ray or hot pixel in your green sub that wasn't in the others. I often see blue dots in some of my images when I don't use median combine. Its just a bit of noise.

Greg.

[astroron]

Greg, I wish you had seen the post and replied sooner;), I sent an email to a professional Astronomer I know with the thread requesting any info on this possible P/N or very green star, and you had posted your reply as I was sending my message:(unbeknown to me
I then got a reply agreeing with your post:rolleyes:
I was surprised Tom didn't see it or know the reason for it being there.

[Jen]

:eyepop:wow Ron how the hell did you spot that i still couldnt see it
even once you circled it :screwy: and yes i still do have 20/20 vision ;)
:whistle:

[astroron]

Hi Jen, I get that asked quite a bit when I have people look through the scope :D It comes with doing lots of observing over twenty odd years, and being naturally a nosey Person;)

[Tom Davis]

I don't think it is a cosmic ray hit. I downloaded off the internet different versions of Omega Centauri taken by other other imagers. After aligning them in Registar my "green star" aligns perfectly with a star in their image. It is not a cosmic ray hit or it would be much more random in location and shape. That said, I do think that is it likely to be just an artifact of processing. Hot pixel likely overlying the star I'd bet. Median combine was used.

Tom

[gregbradley]

Hi Tom,

Yes cosmic rays are more like a little squiggle/worm. By the way I notice there are way more cosmic rays picked up by the 16803 chip. I was surprised when I saw how many there were in my darks. Requires lots of darks to get them out.

I often wonder why some of my images have little green, blue or red dots and others have virtually none.

Perhaps a mismatch of darks and lights somehow?

I notice it happens more if I use say sum combine which is handy for galaxies as it brings slightly more detail out but it leaves the artifacts in.

I often scout around at high zoom in looking for any stray red green or blue dots and healing brush them out. Sometimes there are none, other times there are quite a few. Perhaps slight processing routine changes account for that. Also I have had it that say an asteroid has been in the shot but that is 3 red green blue dots in a straight line slightly apart as it moved whilst being imaged with the 3 different exposures for each filter.


Greg.

[Jen]

:lol::lol: :thumbsup: well there is nothing wrong with your eye site :lol:;)
so dont look at my pics then when i FINALLY get to post one of these days :lol::lol:

[Ric]

Wonderful image Tom, very stunning.

Cheers

[astroron]

Jen I always look at peoples pic's to see if can spot any Supernova in galaxies, and asteroids in nebula and other object pics.
I am not critical of peoples astro photo's as I don't take any myself:)
So you are quite safe:D:D:D

[Jen]

:) phew thats ok then :lol::lol: well maybe i might be the lucky one that takes a pic of one for you one day :lol::lol:
:whistle::whistle: wishful thinking hey :lol: