Centre for Astrophysics and Supercomputing and ARC Centre for All-Sky Astrophysics (CAASTRO), Swinburne University of Technology, Post Office Box 218 Hawthorn, VIC 3122, Australia.
Science. 2011 Sep 23;333(6050):1717-20. doi: 10.1126/science.1208890. Epub 2011 Aug 25.
Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438, a 5.7-millisecond pulsar, was detected in a recent survey with the Parkes 64-meter radio telescope. We show that this pulsar is in a binary system with an orbital period of 2.2 hours. The mass of its companion is near that of Jupiter, but its minimum density of 23 grams per cubic centimeter suggests that it may be an ultralow-mass carbon white dwarf. This system may thus have once been an ultracompact low-mass x-ray binary, where the companion narrowly avoided complete destruction.
毫秒脉冲星被认为是通过从伴星吸积物质而被旋转加速的中子星。虽然大多数脉冲星都在双星系统中，但有 30%左右是孤立的，因此它们的起源是神秘的。PSR J1719-1438 是一颗 5.7 毫秒的脉冲星，最近在使用 Parkes 64 米射电望远镜进行的一项调查中被探测到。我们表明，这颗脉冲星处于一个轨道周期为 2.2 小时的双星系统中。它的伴星质量接近木星，但最低密度为每立方厘米 23 克，表明它可能是一颗超低质量的碳白矮星。因此，这个系统可能曾经是一个超紧凑的低质量 X 射线双星，其中伴星勉强避免了完全毁灭。
