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Type: planetary nebula
Mag: B=11.9, V=9.6
Discovered spectroscopically by Pickering.
The RNGC (Sulentic and Tifft 1973) notes that this is a 11.5 mag planetary nebula.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "12M; 8" diameter; very small; requires high-x and N-filter to see disc; 13.5M star 40" to NNW."
POSS: m14 * 18" due W; m13 * 39" NW. box of *s ~4'x2'.5.
15cm - it ain't! HM, Roof.
- ident @ 50x/80x via UHC blink. sub*ar @ 165x. a couple of vf *s < 1' NW.
BS, 13May1988, TSP.
- ident @ 50x w/[OIII] blink. is SE corner of 4'x2' box w/three sim-br *s
(m11). 165x: sub*ar, 2" diam, hisfcbr. m13 * 20" NW; m14.5-14.8 * at
threshold close (~8"?) to W side. BS, 22May1988, Anderson Mesa.
25cm - seen @ 180x. 244x shows m11 * on W edge, barely separable. nebula little
brtr but lgr. BS.
30cm - sm, not obviously a pn @ 149x. it is the SE corner of a box of m11-12 *s.
238x shows it evenly br, greenish-bluish w/m13 * 1' N. 476x reveals occas
annularity and br spot on E side. m14 * 20" NW. br spot seems like cen *
at 238x. CBL, Roof.
Steve Coe, using a 13" f/5.6, notes: "Small, pretty bright, little elongated at 135X. Not easy to find at this power, it is just barely larger than the seeing disk at medium power. Installing the Barlow to get 270X makes it much easier to recognize. It is a light green dot in a Milky Way field. I estimate 3 arc seconds in size."
Alldays (22.50S, 20.12E, 770m).
12-inch f/10 SCT (218x)
At 76x this planetary nebula is completely stellar, and would be un-distinguable from the other stars in the field of view without the aid of an OIII filter, which shows it prominently when blinked. There is a curving line of three bright stars as wide as the field of view, which points to a double star. Within the curve are two faintish stars, once of which is the planetary nebula. At 218x it is visible with averted vision as a hazy, faint stellar-like object. Additionally I think it may be slightly elongated when I use averted vision. Nebula filter help me out. The star in the middle but not sure comes and go.
The Messier objects
The Bennett objects
The Caldwell list
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