SIMBAD references

The discovery of the pulsar PSR171-19 adds another system to an increasing list of binaries in which a neutron star is accompanied by a companion of rather low mass. In this letter I draw attention to a mechanism that leads to such low companion masses, viz. extreme tidal heating as the orbit circularizes from appreciable eccentricity. This eccentricity arises when the neutron star is formed, or is exchanged into the binary. The same mechanism must operate in the standard scenarios for the formation of low-mass X-ray binaries with short orbital periods.