NGC2442 S shaped galaxy

[gregbradley]

A brief semi clear patch last night so I took advantage of that and picked up 3 hours on NGC2442. I have been wanting to image this galaxy for a long time. Its quite an interesting galaxy. Strange how there are so many different shapes in galaxies around. I wonder why it ends up S shaped rather than a full spiral?

I intend to add more to it if I get the chance. There was a bit of high cloud around at the time as well.

Planewave CDK17, FLI Proline 16803, Astrodon Gen 11, PME mount, 10 minute subs, luminance 1x1 and colour 2x2 at -35C.

LRGB 90 30 30 30.


http://www.pbase.com/gregbradley/image/135257714

Greg.

[multiweb]

Love the colors and details you've got in that one Greg. Really nice. :thumbsup:

[TrevorW]

Definitely S shaped, nice colours Greg

[richardo]

Hi Greg, yes I love this little Gal too.... lots of interesting detail to glean from the interior.
Almost looks as if it is twisting.. if this is possible without other galactic interference??
I think considering your conditions, your perseverance and tenacity has payed off well.
With extra colour and better conditions for your lum, I think this will build from a good image (what you have) to an outstanding one. Definitely worth it with this object!


Just for interests sake, here's a rendition I did in '08
http://www.baytop-observatory.com/ccdimages/galaxies/ngc2442newt.htm

Look forward to the finished version.
All the best
Rich

[renormalised]

Nice shot there, Greg. Like Marc said, really nice colours and lots of detail even in that short space of time.

[gregbradley]

Thanks Marc. It turned out better than I thought it would given the "short" exposure time. Funny how we consider 3 hours a short exposure!



Thanks Trev.Its been on my to do list for years.



Gee that's a nice image Rich. How is it that a 10 inch scope outdoes a 17 inch?? I gotta get my CDK17 to my dark site at some point to see what it is really capable of. I'm going to order a tripod for the PME so I can do that.



Thanks for that. I guess this is where the 17 inch aperture comes into play. It does capture a lot of light fast. It also shows up the seeing good or bad more than other scopes and it also shows up light pollution, thin cloud etc much more as well.

Greg.

[Bassnut]

Geez, I gotta get a 17" ;-). Excellent pic there Greg, jumps right out, dont see this one too often. Top colour, detail etc.

Yes, the 17" aperture sure allows efficient work at that FL, I wouldnt bother with less than 8 hrs or so at 10" (at long FLs), so that means far less output when it takes 3 days or more of imaging, suddenly stuff like weather, moon etc become far more disruptive.

To be able to get a result like that in one night is a huge advantage and makes it all much more fun.

[Doomsayer]

Hi Greg. For an alleged 'quick and dirty' shot, that's a beauty :). One of my favourite galaxies. The 17 really cuts it - c/c Fred's comments.
cheers, guy

[gregbradley]

Thanks Fred. I think also it will require one of the smaller chipped larger pixel cameras to do best in narrowband in a light polluted area. The downside of the Corrected Dall Kirkham design is vignetting. I suppose any compound scope is going to vignette to some degree with these large chips but this one definitely has a bright centre that requires careful flat fielding, Gradient Xterminator, background flattening routines to correct. I don't have that trouble with the 8300 chip but the 8300 chip has small wells and bright stars bloat easily from overflowing wells. So shorter exposures on a small well camera or larger pixel camera.

I think an ST10XME is proven camera with this focal length and would work well. Its kind of a compromise on pixel size (smallish at 6.4 microns) but the high QE and smallish chip just seems to work. I was thinking of getting a 3200 chipped camera or a 6303 chipped camera. I saw a 6303 CDK17 image of M13 which was amazing. I think that would be a very good combo with this scope. Perhaps better than the KAF3200 in some ways if you can handle the blooming (short exposures again unless doing NB). The 09000 chip with RBI control like FLI or Apogee would be good too but then you're back into vignetting a bit. The vignetting would be worse in light polluted areas but at a dark site this scope would be sensational.



Thanks for that. The aperture speeds everything up for sure.

I have an F4.5 reducer on order for it so that will make it even faster to get a good result in a night.

Greg.

[CoolhandJo]

Great shot. Galaxies everywhere! Showcase image!

[Doomsayer]

Getting FLI to put a 6303 chip in your Microline camera would be an obvious solution - the best QE in the medium-large sized class of chips without going to the back thinned ones. Not a cheap chip to buy in class 1 I'd imagine. The 6303 is pretty noisy and would greatly benefit from the superb cooling of the microline - this would be infinitely superior to the 8300 with the CDK if you can stand the blooming. I find the blooming in my 6303 nearly always manageable - except if you go for fields with very bright stars of course. There are also impressive deep wide field NB pics taken with 6303s and FSQs such as my namesake, Neil Fleming. So the 6303 is quite versatile - as is of coure the 'legendary' ST10.

It will be interesting to see how your new reducer goes - hopefully it preserves your current illumination and flat field.

Forgive me if I'm stating the obvious...:D

guy

[renormalised]

Speaking of the chip/pixel combo you're looking for, why not try something like an Alta U42. 13.5micron pixels, bit over 4MP on chip, full well of 100K and it's back illuminated so it's a good deal more sensitive. Chip's about 0.6 x the size of the 16803, so your vignetting mightn't be so bad.

[gregbradley]

Thanks for that. It always amazes me how many galaxies there are in the backgrounds of these images.



The 6303 sounds good. As far as noisy goes how do you mean? I am not to concerned about noise especially if it were in a FLI body. Although an STL6303 would be nice with an AO unit for this focal length. Just to get that bit extra resolution. Or perhaps a microline and an SX AO unit.

Yes I hope the reducer works well too. It does have specs about spots sizes at various spacings so it should not be much of a risk.

But 17 inches at F4.45 and a high QE camera well matched to the focal length perhaps with an AO unit could be a pretty amazing setup. The 16803 for wider fields and something better suited than the 8300 for galaxies etc.



Not a bad idea. I know Peter Ward had one of those and I believe they are quite hard to flat field as they have uneven surfaces and uneven illumination due to the back thinning process.

Wolfgang Promper recently posted some images using one of these high QE back illuminated chips that was quite good. Its not a bad idea.

The 8300 is a good chip its just that its better suited to shorter focal length refractors and shorter exposure times. Mind you on bright objects its pretty awesome on the CDK17 as well. I took an image of the Hourglass Nebula with it and it was the best I have done of that area. No colour yet but I should finish that image, it was very very promising.

Greg.

[renormalised]

I heard that FLI also have a front illuminated version of the E2V CCD42-40 chip as well.

[gregbradley]

Interesting. I'll check it out.

Greg.

[renormalised]

Here's the lowdown at OPT

http://www.optcorp.com/product.aspx?pid=319-320-1116-9418&kw=&st=0

Bit pricey, though!!!!

[Bassnut]

The STX6303 is in production now it seems. With 50deg delta cooling and the tricky guiding features and Ao etc, it would beat the FLI 6303 then I think. Dont know if it has the extra guiding features yet though, SBIG seems to be haveing trouble with that.

[Stevec35]

Not bad at all considering the short exposures Greg. Looking forward to seeing it with more data.

Cheers

Steve

[allan gould]

Very nice image, Greg.
Always great to see what you pull out of the basket next and I just love those little stars around the end of the upper most arm of the galaxy - as if they are framing it. Beautifully executed as well.

[John Hothersall]

I love these curly galaxies, great result.

John.

[Hagar]

Hi Greg, This is lovely Mate. The 17 really does do a nice job on these little galaxies. I have been to see Theo and had a look through his 20" and the view was mind numbing, even in the middle of Melbournes light polution. I can see you are really going to image a lot of the tiny items out there that are really out of reach for most of us.

Great Stuff.

[gregbradley]

Thanks for that. There is a cheaper PL4240 as well.



The STX seems more competitive with its features. Self guiding is very handy.



Thanks Steve. I was happy it turned out well without mega data.



Cheers Allan. The weather forecast looks promising for Sunday night. Perhaps more data can be gotten then.



Thanks John. There seems to be a lot of these unusual galaxies.



Thanks Dougie. I have to confess I haven't looked through the 17 yet.
I definitely need to do that.

[alexch]

What a lovely image, Greg! Brings back fond memories of seeing this "Swan" galaxy visually at SPSP.

[gregbradley]

Thanks Alex. Have you got your Malin awards images ready? You're not gonna let Phil Hart take everything are you? :lol:

Greg.

[gregbradley]

It might be a very nice camera. My main dislike of SBIG cameras is the driver having to be downloaded from the computer to the camera. The FLI and Apogee cameras connect instantly, are extremely stable, and do not lose their drivers even if disconnected from the computer.

If anything interrupts the connection (which seems to happen to me a lot with several of these cameras) then it requires a shutdown and reboot of CCDsoft after repowering up the camera. Perhaps the STX has onboard flash memory so it can retain its driver now.

Also it needs a frame buffer. I am now used to 1 second downloads of 32.4mb images at 1x1 binning. So if it has those things now then it would be a whole lot nicer.

Self guiding would be handy occassionally and an AO unit would also be neat. Self guiding though is no good for Ha or NB. Unless you use a PME or something that will autoguide accurately with 20-30 second guide exposures. Starlight Express now have a large AO unit so perhaps that is the way to go - FLI camera, SX AO unit - best of both worlds.

Also the chamber needs to be sealed with inert gas so no need for dessicants and they never frost. Power plugs and connections are high quality, robust and never fail. Cooling is fast and strong although my Proline does not do the 50C below ambient - more like 45C.

Proline is a heavy camera and can cause even good focusers to flex. Apogee is a bit lighter and a bit narrower. Microline is a good compromise there. FLI has the lowest noise and cleanest electronics. Apogee is also really clean but slow to cool. RBI control is available in both but noone else. If you are using a KAF chip it is nice to have it available (I don't use it though). If you are using a KAF09000 RBI is supposed to be really bad. STX would be heavy as well. It is priced a bit high also. But overall I am sure it is an excellent camera.

Hey did you know there is an 11 mp Sony CCD out now? Starlight Express are selling it. Its probably super low noise.

Greg.

[ving]

great work. never even hear of this one :)

[Paul Haese]

Lovely work Greg. Love the star saturation, the galaxy detail and colour are great and the image looks really flat. If I had any critique at all it would be the back ground looks a tiny bit black and not grey to me, but that is so minor it makes no difference to the image. Lovely work mate. Hoping to get these sorts of results out of the RC12.

Edit, let me retract the black background comment. Just not looking at the right angle. Also is the a lensed galaxy at the orange star in the right hand bottom corner?

[gregbradley]

Thanks. There are lots of these obscure galaxies.



Thanks Paul. That's good about the background as I redid that aspect as one version had the background go too black. There were some gradients and unevenness that I managed to get out.

I think it will come up nicely with another 3 hours.

Perhaps tonight if the weather is clear.

Greg.

[Ross G]

What an amazing galaxy!

A great and unique photo.

Greg, you really are the "Astro Teacher" on this forum!

Thanks.

Ross.

[gregbradley]

Thanks Ross, I appreciate your kind words.

It is clear tonight and I am currently getting another 3 hours or so of additional data which should reduce noise and add a bit more detail.

Greg.