NGC 5882

NGC 5882 is a small^[4] planetary nebula^[3] in the southern constellation of Lupus, positioned about 1.5° to the southwest of the star Epsilon Lupi.^[6] It was discovered by English astronomer John Herschel on July 2, 1834 from the Cape of Good Hope observatory.^[4] John L. E. Dreyer described it as "very small, round, quite sharp".^[7] It is located at a distance of approximately 7.7 kilolight-years from the Sun.^[2]

NGC 5882

Emission nebula
Planetary nebula
A Hubble Space Telescope (HST) image of NGC 5882. Credit: HST/NASA/ESA.
Observation data: J2000 epoch
Right ascension	15h 16m 49.95679s[1]
Declination	−45° 38′ 58.6109″[1]
Distance	7.7 kly (2.4 kpc)[2] ly
Apparent dimensions (V)	13–14″[3]
Constellation	Lupus
Designations	ESO 274-7, IC 1108,[4] NGC 5882[5]
See also: Lists of nebulae

This nebular region consists of the cast-off outer atmosphere of an aging star. It is roughly elliptical in shape with several clumps of ionized material, and is surrounded by a larger region of low-level emission that extends for three times the nominal diameter of the main nebula.^[3] The nebula is expanding with an average velocity of 12.5 km/s. It consists of two shells: the inner shell is elliptical and measures 11″ × 6″, while the more rapidly expanding outer shell is rounder with a diameter of 15″. The inner shell has what appears to be multiple bubble-like shapes. The clumps in the outer shell may be the result of instabilities.^[8]

The elemental abundances of the nebula are very similar to those in the Sun, except for a times two enrichment of nitrogen. The latter suggests that the central star did not go through second dredge-up. The central star has an apparent visual magnitude of 13.43. It shines with 830 times the luminosity of the Sun and has 22.7% of the Sun's radius.^[3] It is displaced slightly from the center of symmetry for the nebula.^[8]