Blue Planetary (NGC 3918)

Blue Planetary, NGC 3918

The Blue Planetary (NGC 3918) is a planetary nebula in the constellation Centaurus, 2.5 degrees northwest of the star Delta Crux, that was discovered and named by John Herschel in 1834. In a 25-centimeter telescope, at low to medium power (75 to 120×), it appears as a small pale blue disk similar to that of Neptune. The image shown here was taken by the Hubble Space Telescope.


visual magnitude 8.1
angular size 12"
distance 2,600 light-years (800 pc)
position RA 11h 50m 18s,
Dec -57° 10' 57'
other designations PN G294.6 + 04.7,
PK 294+04 1, ARO 514