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elpajare

NGC 4236 in Draco. A challenge object

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At apparent magnitude +9.7, NGC 4236 is a tough galaxy for small scopes but rewarding if you can catch it. A 80mm (3.1-inch) telescope reveals a thin needle haze of light that's best seen at low powers using averted vision. Through a 200mm (8-inch) scope the galaxy appears large and faint but with a brighter centre that hints at mottling. Since it spans in total 22 x 7 arc minutes and not far from edge-on, NGC 4236 appears noticeable thin. In larger sized amateur scopes, the galaxy shows much mottling and knotty details along its length with a slightly brighter oval shaped centre. A pleasant view.

NGC 4236 is located 11.7 Million light years distant. It has a radius of 75,000 light-years and is estimated to contain more than 100 billion stars (Freestarcharts)

 

NGC 4236 / GX/  DRACO/ Expo= 20X20" stack/  FWHM=2,6 / ALTIT=57º/  Moon=0 

Skywatcher /f4 + ATIK Infinity + Infinity software

NGC 4236 GX DRACO 20X20 S=2,6 57º L=0 GIMP.jpg

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Thanks for the 'heads up' and a great astro photo. I checked my observing records and it appears that I have never viewed it. I notice that the galaxy is part of the Herschel 615 list so I will make a note to observe it.

Correction I checked Stellarium and I see that the galaxy is Caldwell 3 which I observed in April 2010 - anyway time for a revisit because I now have a larger scope than in 2010.

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As you say a challenge object. This is one I have not seen. I think I discounted it given the low surface brightness!

I will give it a go.

Thanks for sharing it.

Mark

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Excellent capture and informative background information. Well done.

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On August 26. last year, I've "imaged" NGC 4236. It was at the end of a session and regrettable, dew was formed on the corrector plate.

In my observation book I noted: "TO REDO".  I see that May would be the best month to redo, so...

Nevertheless, this was the (poor) result:

Evo 8 @ f/4.6 (f = 937 mm) (FOV: 23' x 18') - Lodestar X2 Mono - Dark area (no moon)

SLL V.3: 6 x 30 s mean

58cf178ee83f4_NGC4236-BarredSpiralGalaxyinDraco-2016.8.27_01_43_25.jpg.8c78f9feaf74218e4559220accb93cc6.jpg

 

Edited by roelb
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Lodestar is a very good camera maybe fast reflector makes the difference?

Or maybe the stack software is the responsable? I don know. Seeing during my shoot was very good, FWHM 2,6 rarely appears here.

Infinity has a stack system that combines addition with mean ( I think) and 20 stacks makes a good difference.

This kind of faint objets looks very well with Infinity instead HII zones are a challenge for it. I have very poor results here.

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I tackled this galaxy on two nights last week (it was still early (for me) before the "moon" came up!). On the first night it was easy to see and filled the ethos21 FOV (in the CPC1100). The shape was quite "boxy" as seen in your image. As @mdstuart says, you expect it to be hard due to its size but it was easily seen :)

I marked it for a return visit!

When I (amazingly) got out again the following night, I found the galaxy harder to see, you could get an outline of the huge size but it was harder to see than the previous night. Movement of the scope enabled it to be more easily seen but it was much dimmer than previoulsy :(

It is nice and high at the moment, so I recommend anyone to have a crack at it next time out. I plan another visit for sure with the new moon coming (and a blacker sky) ...

Alan

Edited by alanjgreen
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2 hours ago, alanjgreen said:

I tackled this galaxy on two nights last week (it was still early (for me) before the "moon" came up!). On the first night it was easy to see and filled the ethos21 FOV (in the CPC1100). The shape was quite "boxy" as seen in your image. As @mdstuart says, you expect it to be hard due to its size but it was easily seen :)

I marked it for a return visit!

When I (amazingly) got out again the following night, I found the galaxy harder to see, you could get an outline of the huge size but it was harder to see than the previous night. Movement of the scope enabled it to be more easily seen but it was much dimmer than previoulsy :(

It is nice and high at the moment, so I recommend anyone to have a crack at it next time out. I plan another visit for sure with the new moon coming (and a blacker sky) ...

Alan

Thanks Alan that is useful information. I am hoping to get a clear spell tonight to give it a go.

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