Planetary Neb PK 231+4.1 in Messier 46

[Preston Pendergraft]

Came across this when looking at some older APODs, I couldn't remember hearing of this one. Did a Google search and found one observation. Thought I would throw this one out to the group!

[Steve Gottlieb]

Preston, here are a couple of observations I made 29 and 31 years ago at a site not far from Lick Observatory.

M 1-18 = PK 231+4.1 = PN G231.4+04.3
07 42 04.1 -14 21 16

17.5" (1/31/87): at 130x + OIII filter; fairly small and round, can hold steadily with averted vision, estimate V = 14.5-15.0. Situated 3.5' NNE of a mag 9 star (SAO 153263) within a small arc of four mag 13-14 stars oriented NW-SE and 22' NNE of NGC 2438 (off the NE edge of M46).

13" (2/23/85): at 79x + Daystar 300 filter; extremely faint, small, round. Near my visual threshold. Easier with an OIII filter but still requires averted vision and concentration.

[Uwe Glahn]

Attention Preston.

PK 231+4.1 = Minkowski 1-18 is not in Messier 46 but around 0,5° north.

PK 231+4.2 = NGC 2438 is in Messier 46.

I have a sketch of M 1-18 with 16", 225x, [OIII] under 7mag skies.
1981

[Paul Alsing]

Attention Preston.

PK 231+4.1 = Minkowski 1-18 is not in Messier 46 but around 0,5° north.

PK 231+4.2 = NGC 2438 is in Messier 46.

I have a sketch of M 1-18 with 16", 225x, [OIII] under 7mag skies.
1981

There is also a proto-planetary nebula in M-46, but it is yet another stinker, OH 231.8+4.2, AKA the "Calabash" or "Rotten Egg" Nebula, @ R.A.: 07h42m16.9s Dec -14°42'52"

Jimi & friends have spotted this guy, here... http://www.deepskyforum.com/showthread.php?75-Calabash-nebula-observation&highlight=calabash

I have tried and failed several times, but so far, no joy :>(

[Preston Pendergraft]

Wow. Awesome some folks have caught this one. I had not even heard of it till I saw it on APOD.

[akarsh]

This is absolutely new to me; didn't know there were two PNs in M46. So, thanks for pointing to it, Preston!