Parkes observations for project P1386 semester 2025OCTS_10

J0045-7319 is a B star/pulsar binary in the Small Magellanic Cloud (SMC) with an orbital period of 51 days. The system is highly eccentric, with a closest approach of only 6 B-star radii, and it offers an unusual probe into massive stars in the SMC. Although similar systems exhibit strong dispersion measure (DM) variation during periastron arising from the stellar wind, observations in 1996 on the Parkes 70 cm receiver found no evidence of a wind from the B star. We propose a new set of observations on the Ultra-Wide Low-frequency receiver (UWL) designed to measure the wind. A null result will decrease the known upper limit on the B-star wind's contribution to DM by a factor of 9.

J0045-7319是小麦哲伦云（Small Magellanic Cloud, SMC）中的B型星/脉冲星双星系统，轨道周期为51天。该系统具有极高的离心率，近心距仅为6倍B型星半径，为研究小麦哲伦云内的大质量恒星提供了独特的观测探针。尽管同类系统会因星风作用在近星点处产生显著的色散量（dispersion measure, DM）变化，但1996年利用帕克斯70厘米接收机开展的观测并未发现该B型星存在星风的证据。我们提议使用超宽低频接收机（Ultra-Wide Low-frequency receiver, UWL）开展新一轮观测以探测该星风。若本次观测得到零结果，将可把B型星风对色散量贡献的已知上限降低9倍。