Identifying a jet-shaped point-symmetric morphology in the supernova remnant HB9

I identify a point-symmetric morphology in the supernova remnant HB9 (G160.9+2.6), supposedly a core-collapse supernova (CCSN) remnant (CCSNR), and attribute this structure to two or more pairs of jets that exploded the star within the jittering-jets explosion mechanism (JJEM). The pairs of jets that shape the point-symmetric morphology of HB9 are part of a larger number of pairs that exploded the star. The point-symmetric structure is composed of a pair of ears, a pair of ears/nozzles, a pair of dents, and a pair of bright bars. Although these pairs of morphological features are small and the point-symmetric structure is subtle, I consider the identification robust. I use visual inspection to identify the point-symmetric morphology of HB9, a method commonly used to identify jet-shaped, point-symmetric morphologies in other astrophysical objects, such as cooling-flow clusters of galaxies and planetary nebulae. I present arguments for jet-driven shaping rather than CSM shaping. These findings support earlier claims that the JJEM is the primary explosion mechanism of CCSNe.