Hi All,
Just think about this _as a guide_. Back in Glen C's post he had a link for an image of the nebula:
http://www.astroimages.com/ic2118.htm
It appears _on the face of it_ that there was no filters used in capturing the image, so leaving aside the relative sensitivities of the emulsion to different wavelengths (galaxy -v- nebula light), all things are pretty much equal.
At the bottom right-hand corner of the nebula in the photo you can see two very small galaxies. The more obvious one is a spindle elongated in about PA 75. This one is NGC 1752 which (pun intended) is:
NGC 1752 Galaxy *
RA: 05h 02m 09.5 Dec: -08° 14' 26"
Mag: 13.3 (B) S.B.: 13.8 B-V: +0.88 Size: 2.6'x0.8'
Class: SB(r)c: P.A.: 70 Inclination: --- R.V.: ---
Source: RC3 *
This galaxy has a surface brightness (SB) magnitude of 13.8, but you will notice in the photo it is considerably higher in surface brightness than the very brightest parts of IC 2118, true? I'd reckon it is at least 3x, maybe 4x higher in SB than the best and brightest bits of IC 2118.
A little way away at the 8 o'clock position from this NGC galaxy is the tiny round galaxy MCG -1-13-49 that almost appears stellar in the photo -- just a fuzzy dot.
MCG -1-13-49 Galaxy *
RA: 05h 02m 37.6s Dec: -08° 18' 04"
Mag: 15.7 S.B.: --- B-V: --- Size: 1.4'x1.2'
Class: SB(rs)d P.A.: 45 Inclination: --- R.V.: --- Source: RC3 *
There is no published SB magnitude (I'm aware of) but after comparing it with the NGC galaxy and given the MCG integrated magnitude of 15.7, at a guess I'd say it is no better than SB mag 15.5 or possiibly a bit worse. You will see it has about the same surface brightness as the very best bits of the nebula.
So, that puts the surface brightness of the best bits of IC 2118 at _about_ the +15.5 mark --maybe a tad better, maybe a tad worse.
That is what you're up agin.
Now, go and start observing some SB mag 14.0, then 14.5 and then 15.0 galaxies and see how you fare. If you can't see 'em, you're almost certainly gonna be outa luck with IC 2118.
Practice, practice, practice !!!
Best of luck in the hunt !!
Best,
Les D
Contributing Editor
AS&T