{"id":3038,"date":"2026-10-23T00:55:12","date_gmt":"2026-10-22T15:55:12","guid":{"rendered":"https:\/\/onepress.co.kr\/?post_type=briefing&p=3038"},"modified":"2026-10-23T00:57:01","modified_gmt":"2026-10-22T15:57:01","slug":"2026-10-23-lightest-neutron-pair-en","status":"publish","type":"briefing","link":"https:\/\/onepress.co.kr\/index.php\/briefing\/2026-10-23-lightest-neutron-pair-en\/","title":{"rendered":"The lightest known neutron-star pair offers another test of gravity"},"content":{"rendered":"

2026-10-23 00:55:12 KST<\/strong><\/p>\n

Analysis using China\u2019s FAST telescope reports PSR J1856\u20130039 as the lowest-total-mass known double neutron-star system.<\/p>\n

An October 21 author interview revisits research published in a September journal issue; this is neither a discovery made today nor a final proof of gravity.<\/p>\n

How the pair becomes a natural clock<\/h2>\n

Neutron stars are extremely dense remnants of exploded massive stars. One member sends regular radio pulses, allowing it to act as a clock. Researchers compared pulse arrival times from 17 FAST observations in 2020\u20132025 with orbital models. The stars orbit in about 2.36 hours. Their masses were not obtained by simply photographing two points of light.<\/p>\n

The record concerns the combined mass<\/h2>\n

The paper reports a total of 2.48841\u00b10.00015 solar masses. Individual estimates are about 1.304 and 1.185 solar masses, each with uncertainty \u00b10.022. Total and individual masses have different precision because different orbital effects constrain them. \u201cLightest\u201d applies to the total among known double neutron-star systems, not all stars or the least massive individual neutron star.<\/p>\n

\"The
AI-generated explanatory illustration, not an actual site, warehouse, exhibited artwork or observation photograph; architecture, water levels and orbits are not reproduced to scale.<\/figcaption><\/figure>\n

What agreement at roughly one percent means<\/h2>\n

The analysis combines orbital decay, rotation of the orbit\u2019s orientation and delays in pulse timing. The ratio of observed gravitational-wave-related decay to the theoretical prediction is 1.009\u00b10.014, reported at 68% confidence. Consistency with one supports the theory; it does not prove it permanently. An already known double pulsar provides a more precise test, so this is not a new precision record.<\/p>\n

The eventual remnant remains uncertain<\/h2>\n

Models predict a merger in about 82 million years, not an observed collision. Whether it leaves a stable neutron star or collapses into a black hole after slowing its spin depends on dense matter. Long-term monitoring may also reveal how spinning mass drags space-time. We compared the authors\u2019 preprint with the recent interview; that interview is not a replication by a separate observing team.<\/p>\n

Primary sources and independent checks<\/h2>\n

Authors\u2019 full preprint: masses, orbit, models and uncertainty; not a claim to have opened the full September PRL version: Yang et al. \u00b7 author preprint \u00b7 arXiv:2607.27333v1<\/a><\/p>\n

Independent reporting: Han email and comparison with a more precise existing test; not a new discovery date or another team\u2019s replication: Live Science \u00b7 2026-10-21<\/a><\/p>\n

Read in other languages<\/h2>\n

\ud55c\uad6d\uc5b4<\/a> \u00b7 English<\/a> \u00b7 Espa\u00f1ol<\/a> \u00b7 \u65e5\u672c\u8a9e<\/a> \u00b7 Ti\u1ebfng Vi\u1ec7t<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

PSR J1856\u20130039 has about 2.49 solar masses in total. A recent interview revisits the result; it does not set the most precise gravity-test record.<\/p>\n","protected":false},"featured_media":0,"template":"","meta":[],"class_list":["post-3038","briefing","type-briefing","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/briefing\/3038","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/briefing"}],"about":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/types\/briefing"}],"wp:attachment":[{"href":"https:\/\/onepress.co.kr\/index.php\/wp-json\/wp\/v2\/media?parent=3038"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}