| Planetary
Nebula
aka M 2-9, PNG 010.8+18.0, PK 010+18.2 Visual Magnitude of Brightest Member: 14.7 Apparent Diameter: 17" Mean Surface Brightness: 20.5 mag/arc-sec2 Magnitude of Central Star: 15.7 Distance: 9100 ly |
Minkowski's Butterfly (M 2-9) is a tiny bipolar planetary nebula. Just detecting it in medium sized instruments can be somewhat of a challenge. Many tiny planetary nebulae have a high surface brightness, making up for their size in apparent brightness. Other planetaries are quite large, but very diffuse and faint. In this case the nebula is both small and relatively faint. High magnification (at least 300x) is required before you can begin to discern the bipolar shape, so a night of good seeing is an asset. In 16-inch and larger instruments this little nebula can be a real treat.
I
spent quite a bit of time trying to view M 2-9 in my old six-inch Newtonian
under very dark skies, but I was never able to even glimpse it. It
wasn't until I finished my 18-inch Dob that I bagged this one. It
took some time to identify the field which is relatively sparse.
At the predicted location appeared a faint star with a tiny ball of faint
haze around it. It wasn't until I put in the 4.8mm Nagler (430x)
that I was able to discern the irregular shape. At this magnification
it became very elongated, splitting into two opposing lobes. A faint
star could be seen in one of the lobes, while the other appeared to have
some sort of irregular feature within it.
Observers using even larger
scopes have described M 2-9 as "remarkable." The OIII and UHC filters
have little, if any, effect on it.
The field in an 10-inch f/8. North is down and east is to the right. The nebula is the tiny smudge near the center.
| Millennium
Star Atlas Vol II Chart 608
Sky Atlas 2000 Chart 7 Uranometria 2000 Vol I Chart 76 |
