The structure of a type-II supernova remnant G 160.5+2.8 (HB-9) observed at ?=12m

A two-dimensional brightness distribution of the old supernova remnant G 160.5+2.8 (HB-9) has been measured at a frequency of 25 MHz with the T-Shaped UTR-2 radio telescope, with the resolution 29′×27′. The source has a distinctly pronounced, almost spherical envelope. At the same time, individual features located near the internal boundary of the source are observable. Certain considerations are put forward to validate a suggestion that the brightest feature in the decameter range (maximum atα=4h55m.3 and δ=46°.37) might be of an extragalactic origin. From structure considerations, the velocity of the pulsar PSR 0459+47 projected on HB-9 is estimated. The estimate does not contradict the hypothesis of Damasheket al. (1978) concerning a possible genetic relation between HB-9 and PSR 0459+47.