SIMBAD references

Following recent discoveries of ultra-long-period radio-loud neutron stars located beyond death line models in the pulsar period-period derivative diagram, we performed a radio pulsation search in the high-mass X-ray binary V0332+53 during quiescence. Although the period and magnetic field of the neutron star in this binary make it the most promising high-mass X-ray binary to explore for this purpose, the GBT observations do not reveal radio pulsations. Here, We present the duty-cycle-dependent flux density limits on the presence of any pulsations and briefly discuss its possible origins: the intrinsic absence or faintness of pulsations, the presence of low-level residual accretion, or eclipses and/or pulse scattering due to the presence of a massive binary companion.