Longmore 8 Planetary Nebula
“The Hamster Wheel”
Description by: Sakib Rasool and Mark Hanson.
Longmore 8, also known as ESO 382-63 and PK 310+24.1, is a delicate celestial ghost haunting the southern reaches of Centaurus. Originally discovered by the professional astronomer Andrew J. Longmore in 1976, this is possibly the most photogenic of the 17 planetary nebulae from the very little known Longmore catalogue. It was independently discovered by the prolific astronomer Lubos Kohoutek and is also catalogued as K1-29.
This planetary nebula represents a fleeting, poetic moment in the life cycle of a star similar to our own Sun. As the central star reached the end of its nuclear fuel, it gently shed its outer layers into the cold vacuum of space, creating a shimmering, translucent shell of ionized gas. Unlike the violent cataclysms of supernovae, this expansion is a graceful transition, where the exposed, scorching-hot core—a fledgling white dwarf—floods the surrounding nebula with ultraviolet light, causing it to glow with a soft, ethereal radiance.
Visually, Longmore 8 is a testament to the intricate symmetry found in the cosmos. Often appearing as a faint, circular, or slightly elliptical smudge against the dense star fields of the Milky Way, its subtle structure reveals the complex interplay between stellar winds and magnetic fields. Because it is relatively low in surface brightness, it remains a hidden gem, typically reserved for the long-exposure eyes of large telescopes rather than a casual glance. To study this nebula is to look into the far-distant future of our own solar system, capturing a final, beautiful exhale of a star before it fades into the dark permanence of a stellar remnant.
Outside of the main central shell is a huge structure of unknown origin consisting of predominantly OIII emission. Ths outer structure was discovered by the amateur astronomer Steve Crouch as a member of the Galactic Planetary Nebula Halo Survey (GPNHS) team in May 2016. His original discovery image can be seen here: https://members.pcug.org.au/~stevec/ESO382-63_STXL6303_RC14.htm
Following the initial discovery of this mystery structure, the very first image to show the full extent of this outer nebula was released by the Atacama Photographic Observatory in April 2017 and can be viewed here: https://www.atacama-photographic-observatory.com/page_photo.php?id=72
This image here includes the entire outer shell and is the second image of this outer structure but represents the first image taken at long focal lengths. The optical resolution combined with 15 hours of OIII exposures not only shows all components of the planetary nebula in unprecedented detail but a possible bipolar outflow is revealed for the first time.
Longmore 8 has an officially recorded size of 132''x110'' in the HASH PN database. The large outer structure is estimated to be 20 arcminutes in size. The possible bipolar outflow has a length of approximately 12.5 arcminutes.
The outer structure is unlikely to be material previously ejected by the central star. Instead its explanation is likely to be a part of the ambient interstellar ISM that was made to be ionized and glow by the energy received from the central star as both it and Longmore 8 move through space.
The bipolar outflow can be seen as two opposing groups of red Ha knots on either side of Longmore 8 and its central star. This is an exciting new structure that this amazingly deep image reveals to the world for the very first time and further proves the importance of deep images of planetary nebulae that lack good quality long focal length images. The presence of a bipolar outflow, which has never been reported previously in either the amateur astronomical realm or in the professional literature is a very likely indicator that the central star is probably a binary system. If confirmed, this would make Longmore 8 even more unique as maybe being the only currently known planetary nebula with a bipolar outflow to be interacting with a region of the ISM.
Age of central star might be 7800 years and the distance might be about 4750 light years.
Further to the right is the spiral galaxy NGC 5121, a reasonably bright galaxy (11.5 magnitude) 1.9' x 1.4' in size.
The coordinates for the exact centre of the large 20 arcminute outer OIII structure are: 13 25 54.63 -37 40 43.7
Imaged in RGBHaO3 on a Planewave CDK 24 at Observatorio El Sauce, Chile. Taken Moravian C5.
60 x 300 sec for each R-G-B, 78 x 600 sec for HA and 90 x 600 sec for O3.
Enjoy,
SWOS Group, Mazlin, Parker, Forman, Magill, Hanson, Sakib
Enjoy, Mark
