A Binary Millisecond Pulsar in Globular Cluster NGC 6544

We report the detection of a new 3.06 ms binary pulsar in the globular cluster NGC 6544 using a Fourier-domain "acceleration" search. With an implied companion mass of ~0.01 M☉ and an orbital period of only Pb ~ 1.7 hr, it displays orbital properties very similar to many pulsars that are eclipsed by their companion winds. The orbital period is the second shortest of known binary pulsars after 47 Tuc R. The measured flux density of 1.3 ± 0.4 mJy at 1332 MHz indicates that the pulsar is almost certainly the known steep-spectrum point source near the core of NGC 6544.