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RA: 18h 12m 2.75s
Dec: −33° 52′ 7.1″
Ch: MSA:1436, U2:377, SA:22
Type: planetary nebula
Mag: B=11.7, V=10
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "planetary nebula. little elliptic, hazy at borders, seen as last night (see next obs)." On a second occassion he called it "A L, F, oval, planetary nebula, about 1' long, 50 arcseconds broad, or 55 arcseconds; considerably hazy, or rather indistinctly terminated at the borders, but not bM; a star 6-7 precedes it, just 1 diameter of the field and nearly in the parallel."
Burnham, S. W. () "Measures of planetary nebulae with the 36-inch equatorial of the Lick Observatory", Pub. Lick Obs., vol 2, p159-167. "This nebula is fairly planetary in appearance, and there seem to be some faint stars in it, but the central star is wanting."
The RNGC (Sulentic and Tifft 1973) notes that this is a 14.0 mag planetary nebula.
Photo Index by Jim Lucyk: Deep Sky #15 Su86 p12.
William P. Clarke (San Diego, California, USA) writes in the The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "A small, oval patch extended N-S. Forms a box with 3 field stars. No central star seen. (10-inch Newtonian, x80)"
Steve Coe, observing with a 13" f/5.6, notes: "Pretty bright, pretty large, round and greenish at 165X. My source says that this object is 13th magnitude. I disagree, it seems more like 12th to me."
In the online Southern Observer (article "The planetary nebulae of Sagittarius") this planetary is recorded as: " This pale blue mag 11.0 disc appears about 40" across in 25cm. The disc is evenly illuminated and is clearly annular wit a bright streak on the W edge. Though it is reported that high powers show it elongated, I see no evidence of it at powers up to x232. The field is crammed with glittering milky way. To find: Locate Epsilon Sagittari, at the SW end of the base of the "teapot". The nebulae is 2-3 low power fields away WNW in the direction of Antares near a group of three mag 6-7 stars. RA 18.12 Dec - 33.8. Winter."
The Messier objects
The Bennett objects
The Caldwell list
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