近日，美国芝加哥大学的R. Luque及其研究团队取得一项新进展。经过不懈努力，他们揭示围绕明亮恒星HD 110067的六颗凌日亚海王星共振现象。相关研究成果已于2023年11月29日在国际权威学术期刊《自然》上发表。

研究团队展示了对附近明亮恒星HD110067周围六颗凌日行星的观测结果。研究人员发现这些行星运行在一系列共振轨道上。通过对最内侧的三颗行星进行动力学研究，成功预测并确认了系统中其他行星的轨道。这六颗行星均属于亚海王星类别，半径介于1.94R_⊕至2.85R_⊕之间。其中，三颗行星的质量已被测量，它们的体积密度较低，暗示着存在以氢为主的大气层。

据悉，在超过半数的类太阳恒星近距离轨道中，科学家们发现了半径介于地球和海王星之间的行星，这些行星被统称为“亚海王星”。然而，目前人们对于这些行星的构成、形成过程以及演化历程所知之甚少。多行星系统的研究为在控制初始条件和环境的情况下，研究行星形成和演化的结果提供了一个机会。特别是那些轨道周期之间存在小整数比关系的共振行星，它们具有特殊的研究价值，因为它们意味着系统结构自形成以来几乎没有改变过。

附：英文原文

Title: A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067

Author: Luque, R., Osborn, H. P., Leleu, A., Pall, E., Bonfanti, A., Barragn, O., Wilson, T. G., Broeg, C., Cameron, A. Collier, Lendl, M., Maxted, P. F. L., Alibert, Y., Gandolfi, D., Delisle, J.-B., Hooton, M. J., Egger, J. A., Nowak, G., Lafarga, M., Rapetti, D., Twicken, J. D., Morales, J. C., Carleo, I., Orell-Miquel, J., Adibekyan, V., Alonso, R., Alqasim, A., Amado, P. J., Anderson, D. R., Anglada-Escud, G., Bandy, T., Brczy, T., Barrado Navascues, D., Barros, S. C. C., Baumjohann, W., Bayliss, D., Bean, J. L., Beck, M., Beck, T., Benz, W., Billot, N., Bonfils, X., Borsato, L., Boyle, A. W., Brandeker, A., Bryant, E. M., Cabrera, J., Carrazco-Gaxiola, S., Charbonneau, D., Charnoz, S., Ciardi, D. R., Cochran, W. D., Collins, K. A., Crossfield, I. J. M., Csizmadia, Sz., Cubillos, P. E., Dai, F., Davies, M. B., Deeg, H. J., Deleuil, M., Deline, A., Delrez, L.

Issue&Volume: 2023-11-29

Abstract: Planets with radii between that of the Earth and Neptune (hereafter referred to as ‘sub-Neptunes’) are found in close-in orbits around more than half of all Sun-like stars. However, their composition, formation and evolution remain poorly understood. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R_⊕ to 2.85R_⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.

DOI: 10.1038/s41586-023-06692-3

Source: https://www.nature.com/articles/s41586-023-06692-3