NGC 4449

[umasscrew39]

NGC 4449 is an irregular Magellanic type galaxy in the constellation Canes Venatici, being located about 12 million light-years away.

Taken with a ZWO ASI533MC Pro on a C11" EdgeHD @f/7 using an Optolong L-Pro filter. SharpCap 90s guided captures were debayered, aligned, integrated, and then post-processed using PixInsight.

NGC 4449.jpg (190.68 KiB) Viewed 1827 times

[oopfan]

Hi, what's the total integration time?

I ran the numbers. It's surface brightness is similar to M81. I could get a good LRGB in 10 hours.

I've drawn the dimensions of the galaxy atop a screenshot of your photo:

NGC 4449 Dimensions.jpg (39.64 KiB) Viewed 1819 times

Thanks.

[umasscrew39]

This is only 3 hrs - not going to get the full galaxy in that time, especially in my sky conditions. I can stretch it a bit more like below but then the core gets blown out. Even if you use the HDR Multiscale Transform tool in PI which works great on M42 to lessen the core, it does not work well on some galaxies like this one as you can see. I'm sure by getting more integration time, this would be a better image and I hate to use LP filters as I am not convinced they help much and can even mess an image up.

integration_ABE.jpg (551.71 KiB) Viewed 1813 times

integration_ABE_2.jpg (546.52 KiB) Viewed 1813 times

[oopfan]

Ah, I see. Thanks for the great follow up. Much appreciated.

I've looked at a few images on AstroBin. The outer extent of the galaxy is a faint glow which I would probably have difficulty picking up with my B5 skies.

Re: LP filters, they take a large chunk out of red-green wavelengths which gives a definite blue cast with OSC's unless corrective action is taken to attenuate blue in PI.

[umasscrew39]

Sure- I'm Bortle 6 and last night was average transparency and below average seeing. And humidity hasn't even arrived yet. Life in the suburbs of Orlando.

[umasscrew39]

Added a few more hours- total integration 6.9 hrs. I think this one is a little better and probably as best I can do in my area.

NGC4449_f.jpg (440.26 KiB) Viewed 1788 times

[oopfan]

I plugged in the info for your telescope, camera, and site.
At your B6 site, 6.9 hours got you to SNR 14.1
At a B5 site, you could get to SNR 19.2
At a B4 site, you could get to SNR 30.6
For you to get to SNR 19.2, you would need a total time of 12.8 hours.
To get to SNR 30.6, you'd need 32.7 hours.

What you have at SNR 14.1 is quite good but it just goes to show how faint the glow is around the galaxy.
From what I've seen of other photos this galaxy isn't worth the heroic effort needed.
If you have an AstroBin account you should post your image. It is very good compared to what is up there now.

Brian

[umasscrew39]

Hey Brian

I agree but that is also why I tried it as it is a bit of a challenge. I use to love the challenge of the Arp catalogue of peculiar galaxies, especially the colliding ones when I lived in the hills of the Bay Area. Where I live now is much more of a challenge and the numbers you presented here is exactly why I've said in the past that I can't see doing 15+ hours on any object. I try to get enough to enjoy the wonder of it, read the science of it, and then move on. I guess that does not make me a "real" astrophotographer but I am content with doing the hobby this way. I could go to darker skies but I built a very nice and $$$ observatory on the roof of my 4 car garage as I like staying at home. So, I sacrifice better skies for comfort and convenience. I can get up at 3 am to see something within a few minutes. I also am sure that my images would look better in the hands of a more experience post-processing individual but learning is part of the fun, too.

Anyway, thanks for the compliment and the info. I posted it on my Astrobin site.

Bruce