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Type: planetary nebula
Mag: B=12, V=?
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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. A perfectly unioform, quite round, planetary disc; like a star out of focus. A very little uncertain at the edges, like a star on a dewy unsettled calm night, when the stars look large without being decidedly ill defined. Diameter = 5 arcseconds, light = a star 9-10th mag. there is positively no bright point in the centre. It has two very small attendant stars, one 14th mag, pos from centre = 352.3 degrees, dist from edge = 3/4 diam; the other also 14th mag, pos 96.7 degrees, dist from edge = 1.5 diameter. Occurs in a field full of milky way stars. (N.B. -- Referring to the description of Dunlop 381, I see no ground to suppose that this can by possibility have been the object intended by that place and description ['an extremely faint small nebula, about 12 arcseconds diameter, with a bright point in the centre']. At all events, the remarkable planetary character has escape notice by the author of that description) See fig 6, plate VI." On a second occassion he called it "planetary nebula, delicate, F, vS, diam = 6 or 7 arcseconds, .exactly round, perfectly uniform (as respects the graduation of the light from the centre to the edges), but the light a very little curdled. Not the slightest haziness, but like a star out of focus. x320 shows rather more fur at the edges than I think it would to a planet of equal size and light. Its light is = a star 10-11th mag. It would be quite useless to look for this object under favourable circumstances -- of instrument and sky. A night of gloriously perfect definition! It is in a very rich place. there are 40 or 50 small stars in field. Measures of the two companions; 1st pos = 351 degrees, dist = 1 diam from edge, star = 14th mag; 2nd pos = 91.4, dist = 2/3 diam, star = 13th mag. Showed it to my attendant, J.S., who saw it well" Later he wrote: "Viewed. I can barely discern that the attendant stars are as in [description above], but it is so faint that (the stars being all blotty and dreadfully defined) I could not be sure it was the object, till too late to take its RA and PD on the wires. However, it was just in the middle of the field at the time expected, and set to the place at once."
It is recorded in the NGC as "a most remarkable planetary nebula, pretty bright, very small, round".
Burnham calls it pretty bright (12th mag.) and very small.
The RNGC (Sulentic and Tifft 1973) notes that this is a 12.0 mag planetary nebula.
A photographic survey of bright southern planetary nebulae. M.N.R.A.S., 110(5), 429-439.
Hartung notes "This small round nebula is quite conspicuous in a star-sprinkled field; it is fairly well defined and brighter towards the centre, and two stars are very close north and following. The nebula is 25 arcsec across".
Sanford calls it a "small round planetary nebula with two stars nearby."
6-inch f/8.6 Newtonian
1998-05-25/26, 6-inch f/8.6 Newtonian, Jonkershoek (exurban). Lim mag 6.2 naked eye; seeing good; dew!
Just north-east of two 8th magnitude stars, appears as a very small, round, gray glow, clearly non-stellar at 104x, probably so at 48x.
1997 April 05, 01:00 SAST, Coetzenburg, 11x80 tripod-mounted binoculars. Not found.
Pale grey fat dot, 25" across, in a very rich field. Has soft edges and an even light across its face. Two stars attend it, almost at right-angles (one north, the other east), with a third fainter star (east-southeast) even closer.
The nebula's diameter is 0.7x the separation between the attendant duo.
Crude sketch made.
Aladin: Duo separation = 36", nebula = 25".
(Uranometria 2000.0 chart)
16-inch f/10 SCT (290x)
Conditions: Relatively Good
Soft disk, slightly gray in color. Outstanding, very round, with 011 filter the edges became slightly misty. Unever string of stars runs from NW to SE for almost 10' on the western side of the planetary.
Instrument:12"Dobsonian Reflector Telescope.
Sky Conditions:The fainter parts of the Milky Way are barely visible.
Transparency of the Sky:Haziness only visible on the horizon.
Seeing:Atmosphere stable with little interference.
First Impression:Planetary Nebula.
Chart Number:No.18(Extract taken out of "Atlas of the Night Sky").
Brightness Profile:High Surface Brightness.
Challenge Rating:Easy to observe in dark skies in a large telescope.
Overall Shape:Oval and well defined.
Is a disk seen? Yes,a small faint oval disk is seen in my 7mm ultra wide angle eyepiece at 214*.
Is the edge sharply defined? No,the edge is not sharply defined,but is well seen as an out of focus star.
What colour is the nebula? Green.
Is there a central star? No.
The Messier objects
The Bennett objects
The Caldwell list
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