MeerKAT's Sensitivity helps rediscover the Binary Pulsar M30B After Two Decades

In a testament to the unmatched sensitivity of the MeerKAT telescope, we have successfully re-detected PSR J2140-2311B, a 13 ms pulsar that had been missing since its discovery in 2001. This pulsar, initially discovered in the core-collapsed globular cluster M30, was suspected to be in a highly eccentric binary orbit. Its elusive nature had left its exact orbital parameters unknown for over two decades.

Using the UHF receivers of the MeerKAT as part of the TRAPUM (TRAnsients and PUlsars with MeerKAT) Large Survey Project, and harnessing the advanced beamforming capability of our backends, we precisely localised the pulsar 1.2(1)’ from the cluster center. This study conclusively determined its orbital characteristics, showcasing a very high eccentricity (e = 0.879) and a 6.2-day orbital period. We also measured the rate of periastron advance, \omega = 0.078 +/- 0.002 deg/yr. Assuming that this effect is fully relativistic, general relativity provides an estimate of the total mass of the system, M_tot = 2.53 +/- 0.08 M_0 consistent with the lightest double neutron star systems known. The formation of M30B likely stemmed from a secondary exchange encounter.

In this talk, I will present a concise overview of these groundbreaking findings from our publication. Furthermore, I'll provide the latest updates from our ongoing timing observations, post-publication, shedding more light on this intriguing binary pulsar. In addition, I will present recent findings from the NGC 6397 cluster, offering more insights into the unparalleled observations MeerKAT provides.