近日，美国国家科学基金会国家光学红外天文学研究实验室的Arvind F. Gupta及其研究团队取得一项新进展。经过不懈努力，他们发现超偏心逆行轨道上的一颗热木星前身星。相关研究成果已于2024年7月17日在国际权威学术期刊《自然》上发表。

该研究团队提出了对TIC241249530b的光谱和光度观测，这是一颗高质量的、凌日温暖木星的行星，其轨道离心率为e=0.94。TIC241249530b的轨道与离心振荡的历史和未来的潮汐圆化轨迹一致。研究人员对变暖木星星族质量和偏心率分布的分析进一步揭示了高质量和高偏心率之间的相关性。

据悉，巨大的系外行星绕着它们的主恒星运行，不太可能形成它们现在的结构。相反，这些“热木星”行星被认为是从冰线以外向内迁移的，并且人们提出了几种可行的迁移通道，包括通过与第三个天体的角动量交换来激发偏心，然后是潮汐驱动的轨道圆化。极偏心(e=0.93)的巨型系外行星HD80606b的发现提供了观测证据，证明热木星可能是通过这种高偏心潮汐迁移途径形成的。然而，没有发现类似的热木星前身星，模拟预测影响这一机制有效性的一个因素是系外行星的质量，因为低质量的行星更有可能在通过近日点时被潮汐破坏。

附：英文原文

Title: A hot-Jupiter progenitor on a super-eccentric retrograde orbit

Author: Gupta, Arvind F., Millholland, Sarah C., Im, Haedam, Dong, Jiayin, Jackson, Jonathan M., Carleo, Ilaria, Libby-Roberts, Jessica, Delamer, Megan, Giovinazzi, Mark R., Lin, Andrea S. J., Kanodia, Shubham, Wang, Xian-Yu, Stassun, Keivan, Masseron, Thomas, Dragomir, Diana, Mahadevan, Suvrath, Wright, Jason, Alvarado-Montes, Jaime A., Bender, Chad, Blake, Cullen H., Caldwell, Douglas, Caas, Caleb I., Cochran, William D., Dalba, Paul, Everett, Mark E., Fernandez, Pipa, Golub, Eli, Guillet, Bruno, Halverson, Samuel, Hebb, Leslie, Higuera, Jesus, Huang, Chelsea X., Klusmeyer, Jessica, Knight, Rachel, Leroux, Liouba, Logsdon, Sarah E., Loose, Margaret, McElwain, Michael W., Monson, Andrew, Ninan, Joe P., Nowak, Grzegorz, Palle, Enric, Patel, Yatrik, Pepper, Joshua, Primm, Michael, Rajagopal, Jayadev, Robertson, Paul, Roy, Arpita, Schneider, Donald P., Schwab, Christian, Schweiker, Heidi, Sgro, Lauren, Shimizu, Masao, Simard, Georges, Stefnsson, Gumundur, Stevens, Daniel J., Villanueva, Steven, Wisniewski, John, Will, Stefan, Ziegler, Carl

Issue&Volume: 2024-07-17

Abstract: Giant exoplanets orbiting close to their host stars are unlikely to have formed in their present configurations. These ‘hot Jupiter’ planets are instead thought to have migrated inward from beyond the ice line and several viable migration channels have been proposed, including eccentricity excitation through angular-momentum exchange with a third body followed by tidally driven orbital circularization. The discovery of the extremely eccentric (e=0.93) giant exoplanet HD80606b (ref.4) provided observational evidence that hot Jupiters may have formed through this high-eccentricity tidal-migration pathway. However, no similar hot-Jupiter progenitors have been found and simulations predict that one factor affecting the efficacy of this mechanism is exoplanet mass, as low-mass planets are more likely to be tidally disrupted during periastron passage. Here we present spectroscopic and photometric observations of TIC241249530b, a high-mass, transiting warm Jupiter with an extreme orbital eccentricity of e=0.94. The orbit of TIC241249530b is consistent with a history of eccentricity oscillations and a future tidal circularization trajectory. Our analysis of the mass and eccentricity distributions of the transiting-warm-Jupiter population further reveals a correlation between high mass and high eccentricity.

DOI: 10.1038/s41586-024-07688-3

Source: https://www.nature.com/articles/s41586-024-07688-3