Author Topic: M31  (Read 1950 times)

Offline ajbarr

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M31
« on: 2013 September 01 09:28:16 »
This is 9 hours of LRGB on M31. I did an HDR merge of an hour of 180s with four hours of 600s and then used HDR Multiscale Transform to control the core. This was imaged with a Takahashi refractor and an SBIG 11000 in Mayhill, New Mexico.

Albert


Offline Alejandro Tombolini

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Re: M31
« Reply #1 on: 2013 September 01 10:35:49 »
Very beautiful Albert!

Saludos. Alejandro.

Offline marekc

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Re: M31
« Reply #2 on: 2013 September 01 11:48:02 »
Oooh, that's a very nice M31, Albert!

The image is nice and deep, and that's something I really enjoy seeing in galaxy images. I get a particular enjoyment from seeing a galaxy image that not only resolves nice details in the spiral arms, but includes a lot of the faint outer halo. And when that halo is reasonably smooth, with a decent SNR... well, one doesn't see that too often. That's a very nice aspect of your image.

I have a question about the framing, because it reminds me of my own efforts to shoot M31 (such as this: http://bit.ly/15qRjF4). I noticed that in your image, the long axis of the galaxy runs roughly from one corner of the image to the other, but it's closer to being along the short dimension of the frame than along the long dimension of the frame. When I was making my first efforts to shoot M31, I didn't realize there was a difference. I just thought "Well, I've oriented my camera such that M31 runs from one corner to another, and the line connecting M32 and NGC 205 will run along the other diagonal." I hadn't set it up quite right, though. The M31 axis should have been closer to the long axis of the frame, and the M32-NGC205 axis should have been closer to the short axis of the frame. That wasn't the case, so I had to start over.

I feel somewhat bad posing this question, because it sounds like I'm saying "hey, did you make a mistake?", and that's rather rude. I guess I'm just curious to find out if any of these ideas were part of how you composed the image. My experience with M31 made me realize how complicated the framing of an image can be, and so I'm always interested to learn about how people framed their images.

Thanks, and very nice image!
- Marek

Offline marekc

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Re: M31
« Reply #3 on: 2013 September 01 11:50:52 »
Hi Albert,

I'm an idiot. I didn't look at your image closely enough. Both the "M31 axis" and the "M32-NGC205 axis" are oriented pretty symmetrically, relative to the long and short axes of the frame.

That'll teach me to shoot my mouth off before closely examining the image! I should have looked at it more carefully before writing my post.

- Marek

Offline ajbarr

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Re: M31
« Reply #4 on: 2013 September 01 12:24:08 »
Alejandro, thank you. And Marek, thank you too. Actually I imaged this M31 remotely. The SBIG 11000 I am using does not have a rotator so I have to set up the image as best as I can without the ability of changing the rotation angle. As you can see I was just barely able to fit the galaxy.

Albert

Offline Nocturnal

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Re: M31
« Reply #5 on: 2013 September 01 14:28:40 »
Lovely job compressing the dynamic range of this target!
Best,

    Sander
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Offline ajbarr

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Re: M31
« Reply #6 on: 2013 September 01 14:58:37 »
Thanks Sander. It's an amazing tool.

Offline marekc

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Re: M31
« Reply #7 on: 2013 September 01 16:00:53 »
Ah, cool! The fixed-position camera made for an extra challenge, and I think the image came out great.

I suppose it could (in theory) be mosaicked, but I'll bet that would require at least a 4-panel mosaic. Yikes, probably not practical. I like your solution.

- Marek

Offline Philippe B.

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Re: M31
« Reply #8 on: 2013 September 02 01:12:56 »
Very nice !!!