New Image Reveals "Pearl" Structure in Supernova Pa 30 Remnant
Astronomers using the Gemini North telescope in Hawaii have produced the most detailed image yet of the Pa 30 supernova remnant. It shows filaments made of near-uniform gas knots, which may help explain how the star survived its explosion.
Astronomers have obtained the most detailed image to date of the Pa 30 nebula, the remnant of a supernova that was likely observed and recorded from Earth in the Middle Ages, in 1181. The new observations were made with the Gemini North telescope in Hawaii and reveal structures that had long gone unnoticed. The study was published in The Astrophysical Journal and could help researchers better understand how stars die.
Filaments like strings of beads
Earlier images had already shown a sphere of long, filament-like strands of matter that together resemble fireworks or a dandelion. The new observations revealed about 10 times more structures than any previous view of the remnant. At this resolution, researchers can see that the filaments are not continuous, as they once seemed. Instead, they look like beads on a string, made of pearl-like knots of gas of fairly uniform size.
Each of these "pearls" is enormous, measuring about four light-days across. Ilaria Caiazzo, a coauthor of the study, said in a press release that the planetary region of our solar system could fit inside each knot about 10 times. She stressed how uniform the knots are and said the team is eager to try modeling them.
Exactly how the pearls formed is not yet clear, though they are assumed to be concentrations of material ejected in the explosion. What is odd is their regularity: after a supernova, astronomers expected far more irregular accumulations, yet the knots are similar in size and appear aligned along the filaments.
A "zombie star"
Pa 30 is also unusual because its central star is not entirely dead. A thermonuclear supernova typically destroys a star completely. In rare cases, however, part of the star survives, and scientists do not yet fully understand how or why. The structures in Pa 30 could help astronomers reconstruct more precisely how such detonations happen and how "zombie stars" live on afterward.
Pa 30 links modern observation with human accounts from more than eight centuries ago. The nebula matches records left by Chinese and Japanese astronomers in 1181, who described a new star in the sky that stayed visible for several months. Centuries later, scientists connected that event to the supernova that produced Pa 30.
