This image was collected over three nights (with the usual beer through the night and Maca's on the way home
) and is a deep rendition of the interacting galaxies in Fornax, NGC 1316/1317.
I framed it to take in the usually overlooked, looping tidal tail/extension, to the lower left of the galaxy in this image, make sure you have
calibrated your monitor in order to clearly see this faint feature
.
Stretching and enhancing the 10hrs of Luminance data (12 inch aperture at F3.8) reveals that when the faint extensions and halo are factored in, this tumultuous galaxy tango field is quite enormous on the sky, covering slightly more sky area than the full moon!!
and it barely all fits in my 38' X 30' FOV!
Cool to note too, that the only bit of recent star formation that has occurred, in either galaxy, is the ring of blue stars encircling the inner regions there in NGC 1317, the rest of the scene looks to be made of rather ancient stars..?
NGC 1316/1317 (click on image and pan around with your cursor)
Enhanced Luminance (to better reveal the very faint tidal tail, various extensions and the massive galaxy halo)
To go galaxy hunting
HERE is the Full Res Full Size version.
A close up look at the complex array of dust lanes, within the inner 2' X 2' core region, is attached to the post and also
HERE
HERE is a comparison with the ESO 2.2m telescope at La Silla
EDIT: How faint can we go?...
Scotty Alder (Tornado33) made an interesting comment regarding this image on Facebook, that gotta me to a thanking....hmmm?
Scott commented that he would like to see me push my big fast scope to see how deep it can go, hey a bloody great idea
...but then I thought, hmm? I took 10hrs with a 300mm dia scope at a fast F3.8 under reasonably dark skies, so I wonder just how deep I had already managed to go..?
So I searched for deep images or even better, quantitative empirical papers on the brightness of some of the faint outer tidal tail regions of NGC 1316. Well low and behold it didn't take long and I found one
A
paper by E. Iodice et al from 2017 shed some very interesting light on my enquiry. This paper used deep imaging data from the ESO VLT Survey Telescope (VST) a 2.6m F5.5 modified Ritchey-Chretien optical layout with a two lens wide-field corrector and located at Cerro Paranal in Chile.
In fact this paper revealed that some of the very faintest structures captured in my data were only identified as recently as 2017 and reported in this paper, the faintest of which (labelled L9 in the annotated image at the link below) shine at an almost impossibly feeble 30.1 mag/squ arc sec!! (which is about 2000X fainter than the core region of the galaxy!)...but never the less, still detectable with amateur equipment
So the initial answer to Scotty's question is..well? in 10hrs worth of 10min exposures through my 12" F3.8 Newt, using a modern commercial cooled CCD camera (SXVR-H694) I can (at least) record faint structures with surface brightness's fainter than 30mag/square arc sec!...that's BLOOD FAINT...in this case, so faint in fact, that even for a significant and regularly studied galaxy like NGC 1316, they weren't identified until just 3 years ago!
Here is the image analysis showing the depth reached (remember to have your
screen adjusted properly with brightness turned up as these features are very faint)
Enjoy
Mike