Last year, I got some mediocre LRGB imaging on NGC1097.   As an experiment, last night I got a further 3 hours of L-band imaging with the Chilescope 500mm Newtonian. 


Adding 3 hours of 500mm aperture L band data to 1 hour each of 200mm aperture RGB imaging, is perhaps pushing the L:RGB ratio to the extreme.  Even more so, considering the RGB data was taken in poor conditions.  

The resultant image shows the jets much better than before, including the faint counter-jet on the other side of the galaxy to the spectacular dog-leg jet.  I also picked up the low surface brightness blobs in the corner of the dog-leg jet and the end of the second-brightest jet.  

[This galaxy brings back fond memories for me.  As a young postdoc, I remember have a fierce debate with Chip Arp, over his claims for non-cosmological quasar redshifts associated with the jets of NGC1097.  My viewpoint  was that the quasars were associated with NGC1097, merely lying in the line of sight.]

However, the image is far from ideal, as I did have to raise the saturation levels to get any colour out of the galaxy and the stars look quite colourless, other than the halo around the brightest star.  Also I had to set the black point a little lower than usual for galaxy imaging.  This results in a less contrasty and less impactful galaxy image, but does reveal the jets, missing from many pictures of this object.

The loss of colour of in the stars is, I suspect, a function of the L:RGB ratio used, and the fact that the L-band data was taken with 600sec exposure, not 300sec, further saturating the wings of the bright stars.  I will definitely return to this object to taken more, better and longer RGB subs to balance up the L.  But, in the meantime I thought it was worthwhile posting to show what one can get away with, using an effective L: RGB ratio greater than 10:1.   Thanks again to @Michael Feigenbaum for suggesting this approach. 

17 x 600s L
12 x 300s R
12 x 300s G
12 x 300s B