M94

[alan4908]

For some reason, I've never imaged M94, so here's my attempt at this very unusual galaxy. 

M94 is approximately 17 million light years distant and contains both inner and outer rings.  Star formation occurs in both rings but is mainly concentrated in the inner ring which is also known as a starburst ring, within this region, the rate of star formation is occurring so fast that it will exhaust the available interstellar gas supply well before the death of the galaxy.  The extensive outer ring contains about 20% of the galaxies mass and consists of spiral arms when viewed in IR/UV,  however, in  visible light it appears as a halo.  Exactly how the outer ring formed is subject to debate.  Past theories include gravitation interaction with a nearby star system or accretion of a satellite galaxy, however, problems have been identified with each of these theories.  It is also strange that in 2008 a study indicated that M94 also seems to have little or no dark matter, which is very odd since it is inconsistent with current galaxy formation models.  So, all in all, a very mysterious object. 

The LRGB image below represents just over 13 hours and was taken with my Esprit 150.

 

 

LIGHTS: L:26, R:19, G:18. B:17 x 600s; DARKS:30, FLATS:40, BIAS:100 all at -20C.

[alan potts]

A stunning shot, then when you consider it is taken with just over a meter and this isn't exactly M31 size, even better than stunning. Great capture.

Alan 

[barkis]

Superbly captured, it looks fantastic, and I like the dialogue  supplied with this object.
It adds much to the value of  the image itself.
Nice indeed.
Ron.
 

[MarkAR]

Very nice image. The central region looks really strange. Like a bad cut and paste from another galaxy ! Weird.

[FaB-Bo-Peep]

This is one of my favourite objects and you've captured it stunningly!

[alan4908]

20 hours ago, alan potts said:

A stunning shot, then when you consider it is taken with just over a meter and this isn't exactly M31 size, even better than stunning. Great capture.

Alan 

Thanks for the comment Alan.  The faint halo rendition was helped by application of a so called superluminance (constructed from the noised weighted L, R, G, B stacks), deconvoluting this also helped in extracting the detail. 

19 hours ago, barkis said:

Superbly captured, it looks fantastic, and I like the dialogue  supplied with this object.
It adds much to the value of  the image itself.
Nice indeed.
Ron.

 Thanks - yes - I found it interesting to read up and understand a little more about this mysterious object.

15 hours ago, FaB-Bo-Peep said:

This is one of my favourite objects and you've captured it stunningly!

Thanks 

Alan

[Allinthehead]

Great image Alan, you've managed to extract plenty of detail.

[wimvb]

Great capture. The structure in the faint outer ring is just starting to show. And you kept the core under control too. I’m still struggling with my version. This is a hard one to get right. 👍

[alan4908]

16 minutes ago, Allinthehead said:

Great image Alan, you've managed to extract plenty of detail.

Thanks - yes,  I was very happy with the detail on this one,  helped by the superlum + deconvolution approach mentioned above. 

1 minute ago, wimvb said:

Great capture. The structure in the faint outer ring is just starting to show. And you kept the core under control too. I’m still struggling with my version. This is a hard one to get right. 👍

Thanks - Yes, I did find this difficult to process. 

An Adam Block PI technique that I found of use when processing this:  given the very high dynamic range of the object,  after HT stretching it so that you can see the halo, use HDMRT but only via selecting a preview with the preview encompassing the "blown out" parts.  Then apply HDMRT to the preview.  Use the script substitute with preview to obtain the result.   You may need to blend in the result with the original image, so that you don't see the join.  You may also need to repeat this technique twice, for example, once to the very bright areas and once to the bright areas. 

Alan

[alan4908]

23 hours ago, MarkAR said:

Very nice image. The central region looks really strange. Like a bad cut and paste from another galaxy ! Weird.

Thanks - yes, I agree about the appearance, it does look odd. In fact, everything about this galaxy seems a little strange and mysterious.  

Alan