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NGC 4395 unbarred spiral galaxy

Jedi2014

By Jedi2014
in Imaging - Deep Sky

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Jedi2014

Jedi2014

Posted
Posted

It's me (again),

and I have another dwarf galaxy in my pocket. Dwarf galaxies have affected me somehow. Apart from the fact that every time it is a challenge to image it in a reasonable way, I'm also challenged by the fact that there are not as many amateur pictures as for the standard galaxies.

NGC 4395 is an unbarred spiral galaxy of some 55 thousand light-years across that lies around 15 million light-years away from Earth in the northern constellation of Canes Venatici, while it is receding from us at about 319 kilometers per second. It is a chaotic, low surface brightness galaxy with a center of no more than two light-years across - less than half the distance from our Sun to the nearest star. The galaxy is dominated by several bright emission nebulae (HII regions) and has an active galactic nucleus, which gives off prodigious amounts of energy largely in the form of high-energy x-rays and gamma rays, which classifies NGC 4395 as a Seyfert galaxy. The centers of Seyfert galaxies usually contain supermassive black holes with masses between 10 and 100 million solar masses. However, NGC 4395 is notable for containing one of the smallest supermassive black holes ever discovered, with an accurately-determined mass. The central black hole has a mass of “only” 300,000 solar masses, which would make it a so-called “intermediate-mass black hole”.

So, it is an interesting target and I hope you will like the image...

ngc4395-lrgb-small.jpg

Data: http://www.spaceimages.de/en/astrophotos/galaxies/ngc-4395
or: http://www.astrobin.com/293431/

Greetings
Jens

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Jedi2014

Jedi2014

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3 hours ago, Paul73 said:

Great image. And, thanks for the write up. It brings the image to life!

Paul

 

Thanks Paul. You're right, a little bit of background information makes an image more interesting, if it is not often seen.

 

1 hour ago, Allinthehead said:

Nice image Jens.

Many thanks.

 

1 hour ago, coatesg said:

Great image Jens - the 10" newt looks to be performing very well! And a very interesting, and not often seen subject too. :)

Thank you Graeme, yes my newt is nice and I love it :-)
I did never expect to hear me saying that, but I like it more than my Takahashi FSQ85. The 10 inch, f4  can collect so much light in a relatively short time - the right thing for a medium light polluted sky.

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Jedi2014

Jedi2014

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Hi everybody, I am very happy to see that this galaxy may have got some new friends and it may imaged a little bit more often in the future. If I had more patience and would invest double the time in it, I am sure the details would come out much more crispy. (Quite many "woulds") :-)

michael I am very curious to see your result. If you like and if it fits to my field of view, we could put our data together and see what happens.

Jens

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michael8554

michael8554

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23 hours ago, michael8554 said:

Hi Jens

Several hours into imaging this same object as I write this, though not expecting to compete with your quality.

Michael

I managed 7 x 600secs before the clouds rolled in.

The object is large but quite dim, so a quick stack of those 7 subs looked like one sub of M95 !

So at this rate I will need many more evenings to get a half-decent result.

Michael

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Thommy

Thommy

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Hallo Jens,

I only saw this nice capture now - it's really magnificent - nice color, good tracking, not too dark background etc.

I noticed on your homepage that you use off axis guiding on your newtonian - do you have any problems with that setup? Sometimes you hear people saying that OAG and newtonians is not a good fit.

When I started studying astronomy back in 91' I was also attracted by dwarf galaxies somehow. Perhaps because each dwarf galaxy is unique - there is no "typical" dwarf galaxy. Also their stellar generations are well separated in time which allows us to study each generation isolated for the others. There were no scientists who worked with dwarf galaxies at Copenhagen University at the time, I was ready to decide for a thesis, but I discovered that there was a British professor at Nordita in Copenhagen, who had worked with dwarf galaxies for many years. It turned out that he was very enthusiastic to become my instructor for my thesis - what a wonderful time! Now astronomy is just my hobby.

/Thommy 

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Jedi2014

Jedi2014

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Thanks Paddy and Tommy,

Tommy, I have no trouble with OAG and newt at all. Just the opposit. First I used an MGEN stand alone guider with the newt - which I used with my Takahashi as well. But I recognised some kind of field rotation in longer exposures. May be a main mirror shifting. After I switched to OAG, guiding is unproblematic. Only issue is to keep the correct distance between corrector and camera, if you add an OAG. In my case I have to use a very short one (only 11 mm, the TSOAG09 from Teleskop-Service Germany) to fit the distance of 55mm in my image train.

Jens

 

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ollypenrice

ollypenrice

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Really first class, Jens. Superb imaging and an excellent write-up, as others have said. We used to have Picture of the Week on here and this would have been my choice without hesitation.

Olly

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Jedi2014

Jedi2014

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Hi Olly and Peter,

thanks a lot for watching and commenting so nice. I feel honored.

Peter, of course the raw data do not have 100% the look of the final image - at least at the first sight. But all information you see in the processed final image are in there, you only have to pull them out. In my latest thread (NGC 4725 - closer view) I showed two raw luminance images. It gives you a feeling how the quality of the newt is out of the box. I have to admin that processing skills are critical to the ultimate image impression.

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