NGC 2867

NGC 2867 (Caldwell 90) is an elliptical planetary nebula of Type II in the southern constellation Carina, located a little more than one degree north-northwest of the star Iota Carinae. John Herschel discovered it on April 1, 1834, and initially suspected it might be a new planet, but a check the following night showed it had not moved. The nebula lies about 7,270 light-years from the Sun.

Its central star has spectral type WC3 and is evolving into a white dwarf, having previously shed the atmosphere that formed the surrounding nebula. This star is a hydrogen-deficient GW Vir variable, exhibiting non-radial pulsations with an amplitude under 0.3 in magnitude. Its estimated temperature is 165+18−20 kK, its radius is about 5% of the Sun’s, and it shines with 1,400 times the Sun’s luminosity.

The nebula itself is fairly typical but shows carbon enrichment, suggesting the progenitor star was not massive but underwent a third dredge-up. The central star’s category has produced a very high degree of ionization in the nebula. The nebula’s shape is somewhat elongated, possibly due to interaction with surrounding interstellar matter. Its halo may be a recombination of two separate halos, hinting at an unusual mass-loss history.