美国国家航空航天局两项研究显示LISA引力波天文台可揭示双白矮星系统中的系外行星：木星质量行星可在数千光年外被探测，成果发表于《天体物理学杂志》
美国国家航空航天局于 2026 年 11 月 10 日发布，由该局天体物理学家领衔的两项研究显示，正在研制中的 LISA（激光干涉仪空间天线）引力波天文台可以揭示银河系内一类全新的系外行星群体。两篇论文当日发表于《天体物理学杂志》。
研究针对双白矮星系统。白矮星是类太阳恒星留下的地球大小的残骸。马里兰大学巴尔的摩分校与美国国家航空航天局戈达德航天飞行中心（位于马里兰州格林贝尔特）的博士后研究员 Casey McGrath 表示，LISA 预期最常见的信号源是双白矮星系统，即两颗白矮星在紧密轨道上互相绕转；如果一颗系外行星也在这样的系统中绕转，它的存在会印刻在引力波信号上，可以被揭示出来。
原理上，行星的引力会牵引其宿主系统产生反射运动，给引力波信号加上多普勒调制，在主信号频率两侧形成边带。第一篇由 McGrath 独著的论文考察了这一探测方法，并确定该方法最适用的行星质量与轨道周期范围；第二篇由 McGrath 与合作者撰写，研究如何用美国国家航空航天局的詹姆斯韦布空间望远镜确认这类行星。
团队给出的量级包括：LISA 可在数千光年外探测到这类系统中的木星质量行星；银河系内估计有 1000 万个轨道周期小于 1 小时的双白矮星系统，LISA 预计可分辨其中约 1 万个系统。韦布望远镜的红外方法可在至少 500 光年距离内探测红外过量，在一个该距离的测试系统上可探测约 5 倍木星质量的行星。
LISA 由欧洲空间局主导，计划于 2030 年代中期发射。美国国家航空航天局作为合作方提供望远镜、激光系统等关键硬件与工程科学支持。LISA 由三艘航天器组成三角形阵列，每边长 160 万英里（250 万公里）。围绕双白矮星系统探测系外行星的想法最早由日本天文学家 Naoki Seto 于 2008 年提出。
Two NASA-Led Studies Show the LISA Gravitational-Wave Observatory Could Reveal Exoplanets in Double White Dwarf Systems: a Jupiter-Mass Planet Detectable Thousands of Light-Years Away, Published in The Astrophysical Journal
NASA said on November 10, 2026, that two studies led by NASA astrophysicists show in new detail how the LISA (Laser Interferometer Space Antenna) observatory, now in development, could reveal a new and unique population of exoplanets throughout the galaxy. The two papers were published the same day in The Astrophysical Journal.
The studies target double white dwarf systems. White dwarfs are the Earth-sized remnants of stars like the Sun. Casey McGrath, a postdoctoral researcher at the University of Maryland, Baltimore County and NASA Goddard Space Flight Center in Greenbelt, Maryland, said the most common source for LISA is expected to be double white dwarf systems, and that if an exoplanet also orbits within one of these systems, its presence becomes imprinted on the gravitational wave signal in a way that can be uncovered.
In the method, the planet gravity tugs on its host system, imparting a reflex motion that adds a Doppler modulation to the gravitational signal, appearing as sidebands at higher and lower frequencies than the primary signal. The first paper, authored solely by McGrath, examines the detection method and determines the planet masses and orbital periods where it would work best. The second paper, by McGrath and coauthors, investigates how such planets could be confirmed using NASA James Webb Space Telescope.
The team estimates cited by NASA include that LISA could detect a Jupiter-mass planet in such systems up to thousands of light-years away, that the Milky Way contains an estimated 10 million double white dwarf systems with orbital periods of less than an hour, and that LISA is expected to resolve about 10,000 individual systems. The Webb infrared method can detect an infrared excess out to at least 500 light-years, and for a test case system at that distance could detect an exoplanet about five times Jupiter mass.
LISA is led by ESA (the European Space Agency) and is slated for launch in the mid-2030s, with NASA contributing telescopes, the laser system and other critical hardware and support. The observatory will consist of three spacecraft forming a triangular array stretching 1.6 million miles (2.5 million kilometers) on each side. The possibility of detecting exoplanets around LISA double white dwarf systems was first proposed by Japanese astronomer Naoki Seto in 2008.
来源： https://science.nasa.gov/missions/lisa/gravitational-waves-can-reveal-new-worlds/
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图片来源：美国国家航空航天局固定图库（GSM asset-packs）
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