美国空间望远镜科学研究所K. K. W. Hoch团队研究了YSES-1系外行星系统中的硅酸盐云和环行星盘。相关论文于2025年6月10日发表在《自然》杂志上。

年轻的系外行星在理解行星形成和大气演化之间提供了关键的联系。直接成像光谱学使人们能够以高信噪比推断年轻、宽轨道、巨行星的特性。这使研究组能够将这个年轻的群体与以透射光谱为特征的系外行星进行比较，透射光谱间接揭示了云层、光化学和大气成分的多样性。也对褐矮星进行了直接探测，但在JWST之前，不可能对中红外波段的年轻巨行星进行直接研究。 

YSES-1系统有两颗系外行星围绕着一颗太阳型恒星，是研究系外行星演化早期阶段的理想实验室。研究组报告了通过其9-11µm的吸收特征对系外行星YSES-1 c大气中硅酸盐云的首次直接观测，以及围绕其兄弟行星YSES-1b的第一次绕行星盘硅酸盐发射。YSES-1c的云由无定形富铁辉石或无定形MgSiO₃和Mg₂SiO₄的组合组成，在1毫巴的压力下粒径≤0.1μm。他们将YSES-1b周围星盘的发射归因于亚微米橄榄石尘埃颗粒，这些颗粒可能是通过星盘中行星形成体的碰撞形成的。

附：英文原文

Title: Silicate clouds and a circumplanetary disk in the YSES-1 exoplanet system

Author: Hoch, K. K. W., Rowland, M., Petrus, S., Nasedkin, E., Ingebretsen, C., Kammerer, J., Perrin, M., DOrazi, V., Balmer, W. O., Barman, T., Bonnefoy, M., Chauvin, G., Chen, C., De Rosa, R. J., Girard, J., Gonzales, E., Kenworthy, M., Konopacky, Q. M., Macintosh, B., Moran, S. E., Morley, C. V., Palma-Bifani, P., Pueyo, L., Ren, B., Rickman, E., Ruffio, J.-B., Theissen, C. A., Ward-Duong, K., Zhang, Y.

Issue&Volume: 2025-06-10

Abstract: Young exoplanets provide a critical link between understanding planet formation and atmospheric evolution1. Direct imaging spectroscopy allows us to infer the properties of young, wide orbit, giant planets with high signal-to-noise. This allows us to compare this young population to exoplanets characterized with transmission spectroscopy, which has indirectly revealed the presence of clouds2-4, photochemistry5, and a diversity of atmospheric compositions6-7. Direct detections have also been made for brown dwarfs8-9, but direct studies of young giant planets in the mid-infrared were not possible prior to JWST10. With two exoplanets around a solar type star, the YSES-1 system is an ideal laboratory for studying this early phase of exoplanet evolution. We report the first direct observations of silicate clouds in the atmosphere of the exoplanet YSES-1 c through its 9-11 μm absorption feature, and the first circumplanetary disk silicate emission around its sibling planet, YSES-1 b. The clouds of YSES-1 c are composed of either amorphous iron-enriched pyroxene or a combination of amorphous MgSiO3 and Mg2SiO4, with particle sizes of ≤0.1 μm at 1 millibar of pressure. We attribute the emission from the disk around YSES-1 b to be from submicron olivine dust grains, which may have formed through collisions of planet-forming bodies in the disk.

DOI: 10.1038/s41586-025-09174-w

Source: https://www.nature.com/articles/s41586-025-09174-w