Quote:
Originally Posted by ngcles
Hi Shell,
Very well done mate in finding NGC 3918. In my experience it only very rarely shows much in the way of detail apart from being evenly illuminated, round and a strong turquoise/cyan colour.
Only twice before have I ever suspected further detail and here is an observation from 2009 when the seeing was a "good" 8/10 allowing very high magnifications (x634) to be used successfully while retaining sharp, near pinpoint stars:
x634 8' TF
NGC 3918 Planetary Nebula *
RA: 11h 50 18.1s Dec: -57° 10' 58"
Mag: 8.4 (P) Size: 19.0" Class: 2b Mag C. Star: 15.6
Astonishing seeing -- never seen detail in this thing like this before. Unfiltered at this magnification the disc of this PNe is about 15" diameter and a pale steely blue -- different from low magnification view. Never seen it other than round before. There are two nearby stars mag 10 to the E 4' and the SE 5' and from those the nebula is elongated in PA 0, more correctly, it is round but has two small, low protrusions from the disc N and S that make it look slightly oval in PA 0. The protrusions from the disc are slightly lower in SB than the rest of the disc and *occasionally* there seems to be a hint of some mottling over the disc. No Central star. Lots of mag 14 & 15 *s in the field. Fantastic seeing.
Since I have owned this 46cm, on nights where the seeing is exceptional (very rare) I spend almost all my time on PNe. I see I have recorded the colour as steely blue rather than the familiar cyan. This is almost certainly the result of high magnification that spreads the disc over a larger area of the focal plane, decreasing the colour-effect.
Best,
Les D
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Thanks so much Les, I am positively chuffed about finding it
Nothing like that rush when you find an elusive object! Thanks for your help yesterday, it really did make it easier to find keeping that knowledge in mind!
Goodness, that observation sounds incredible! I hope one day to get a view of it as good as that! It was very in and out viewing it, it would be crisp then blobby then crisp. I swear I did see a bit of a halo but who knows, could have been my eyes playing tricks on me. But from looking at pictures of it, I think I did see the slightest hint of detail. But very, very slight and pretty blah conditions.
Oh well, I found it
Now I know where to look next time!