近日，法国巴黎索邦大学J. Osorno团队发现了一颗对人马座A*自旋敏感的恒星。相关论文发表在2026年8月19日出版的《自然》杂志上。

人马座A（Sgr A）位于银河系中心，是距离我们最近的大质量黑洞。其近邻区域使得学界能够测量围绕它的单颗恒星轨道。这些恒星充当测试粒子，探测着这个4.3×106倍太阳质量（M⊙）黑洞周围的引力势。

这些观测已以优于百分之一的精度确定了中心质量，而恒星具有的弱相对论性运动使学界得以获取主导的相对论修正项——引力红移、横向多普勒效应以及由势场的史瓦西度规性质所决定的顺行进动。这些效应量级为β2= (v/c)2（其中v为速度，c为光速）。旋转黑洞的克尔度规则带来β3量级的修正。

研究组报告发现了一颗暗弱的主序星（mK = 19.3），编号S301，其轨道周期为8.7年，且近心点距离足够小，使得该恒星的峰值速度达到25,000 km/s。在当前近红外干涉测量和未来极大望远镜光谱观测的测量能力范围内，S301的运动将直接敏感于Sgr A*的自旋。S301的高偏心率表明，它是一颗双星系统中被希尔斯机制撕裂后捕获的成员。

附：英文原文

Title: Discovery of a star sensitive to the spin of Sagittarius A*

Author: Abd El Dayem, K., Abuter, R., Aimar, N., Amaro-Seoane, P., Berdeu, A., Berger, J.-P., Bourdarot, G., Brandner, W., Burkert, A., Caldron, D., Correia, C., Cuadra, J., Davies, R., Defrre, D., Delit, L., Drescher, A., Eisenhauer, F., Esteras Otal, L., Fabricius, M., Feuchtgruber, H., Flesch, S., Frster Schreiber, N. M., Foschi, A., Fournier, Q., Garcia, P., Garcia Lopez, R., Generozov, A., Genzel, R., Gillessen, S., Gont, F., Haubois, X., Hnig, S. F., Houll, M., Joharle, S., Kaufer, A., Kammerer, J., Kervella, P., Kolb, J., Kreidberg, L., Labadie, L., Lacour, S., Lai, O., Laugier, R., Le Bouquin, J.-B., Leftley, J., Li, R., Lopez, B., Lutz, D., Mang, F., Mrand, A., Millour, F., Montargs, M., Morujo, N., Nowacki, H., Nowak, M., Oberti, S., Osorno, J., Ott, T., Paumard, T., Paladini, C., Pappert, S., Perets, H. B., Perraut, K., Perrin, G., Petrov, R., Petrucci, P. O., Piran, T., Pourr, N.

Issue&Volume: 2026-08-19

Abstract: Residing in the centre of the Milky Way, Sagittarius A* (Sgr A*) is the closest massive black hole1 (MBH). Its vicinity has allowed measuring individual stellar orbits around it2,3,4. The stars act as test particles and probe the gravitational potential around the 4.3 × 106M⊙ MBH. These observations have determined the central mass to sub-per-cent precision5, and the mildly relativistic motions of stars have given access to the dominant relativistic corrections, the gravitational redshift6,7, the transverse Doppler effect and the prograde precession imposed by the Schwarzschild metric nature of the potential8. These effects are of order β2 = (v/c)2 (for velocity v and speed of light c). The Kerr metric for a rotating black hole leads to corrections of order β3. Here, we report the discovery of a faint main-sequence star (mK = 19.3), S301, on an 8.7-year orbit and with small enough a pericentre distance, such that the peak velocity of the star reaches 25,000kms1. Within the measurement abilities of current near-infrared interferometry and future spectroscopy on an extremely large telescope, the motion of S301 is directly sensitive to the spin of Sgr A*. The high eccentricity of S301 suggests that it is the captured component of a binary that was torn apart by the Hills mechanism.

DOI: 10.1038/s41586-026-10894-w

Source: https://www.nature.com/articles/s41586-026-10894-w