The Caldwell Objects

90
9 0
NGC 2867
Type: Planetary Nebula
Con: Carina
RA: 09 h 21 m 25.3 s
Dec:-58° 18'41"
Mag: 9.7
Diam: 11"
Dist: ~5,500 light-years
Disc: John Herschel, 1834
J. H ERSCHEL: [Observed 1 April 1834]
The finest planetary nebula I ever
remember to have seen for sharpness
of termination; 3 arcsec[onds in]
diameter; exactly round; no more
haziness about them than would be
about a star of the same magnitude to-
night (which is a favourable one).
Light, a pale white =
star of 9th magnitude]. Position [angle] of companion star = . . . 58.6°;
star = 15th magnitude]. A very remarkable object. Showed to [John]
Stone, who distinctly perceived the total difference of appearance
between it and a star [of] 9th magnitude] very near it. A second
companion star suspected (at about half the distance of the 1st by
diagram, and at an estimated position [angle] of 330 [°]) among [a]
multitude of
O N A PRIL 1, 1834 — OUR A PRIL F OOLS' Day
— John Herschel was sweeping the southern
heavens with his 18¼-inch reflector when he
chanced upon a nebula so sharp and round that
he believed it to be a new planet. The object
measured 3", as Herschel saw it, and it resembled
the planet Uranus, which his father had
discovered in 1781. Herschel's heart must have
pounded with excitement over the pros-
large and small stars, (h 3163)
GC: Remarkable, a planetary nebula equal to a star of 8th
magnitude, 59° 8', 13" wide.
NGC: Remarkable, a planetary nebula equal to a star of 8th
magnitude, very small, round, a single star of 15th
magnitude, position angle 59°, 13" wide.
pect that he might follow in his father's footsteps
and contribute to the expansion of the solar
system. Anticipating that the object would move,
John Herschel meticulously measured its position
relative to nearby field stars. He wrote of a 15thmagnitude
"companion," which he presumably
suspected to be a moon of the putative planet. No
motion, however, was detected that night. And
though the fol-
354 Deep-Sky Companions: The Caldwell Objects