A stellar bubble adrift in a sea of ionized gas
ESO 382-63 presents a striking example of a planetary nebula embedded within an expansive emission structure, located in the southern constellation Centaurus. The central object is a classic spherical shell produced during the late evolutionary stages of a Sun-like star, now expelling its outer layers into the surrounding interstellar medium. The nebula displays a well-defined circular morphology with internal filamentary structure, shaped by interacting stellar winds and earlier episodes of mass loss
At an estimated distance of roughly 6,500 light-years, the bright inner shell spans about 1.5 light-years in diameter, corresponding to an apparent angular size of approximately 50 arcseconds. Its vivid pink coloration arises from strong hydrogen emission, while the broader, more diffuse envelope rendered in blue traces oxygen emission extending several arcminutes across, indicating a much older and more extended outflow interacting with the surrounding medium
The nebula’s age can be estimated from its physical size and typical expansion velocities of planetary nebulae. With an expansion speed on the order of 20–30 km/s, the bright inner shell is approximately 20,000 to 30,000 years old. This places ESO 382-63 in a moderately evolved phase, where the central white dwarf continues to ionize the expanding shell. The much fainter outer structures likely originate from earlier mass-loss episodes and may be significantly older, preserving a longer record of the progenitor star’s final stages
Subtle asymmetries in the outer arcs and variations in brightness suggest interaction with the interstellar medium or directional mass ejection during the star’s final phases. Over time, this nebula will continue to expand and dissipate, enriching the surrounding space with processed material and contributing to the ongoing cycle of stellar evolution
Imaged in Ha OIII and RGB on the ASA Astrosysteme AZ 1500 at Observatorio El Sauce, Chile.
Image Acquisition and Processing: Mike Selby