发表机构
Northern Arizona University; University of Victoria; National Research Council of Canada, Herzberg Astronomy and Astrophysics Research Centre; Space Telescope Science Institute; University of Pennsylvania; Center for Astrophysics — Harvard & Smithsonian; University of Michigan; Universidad de Chile（北亚利桑那大学; 维多利亚大学; 加拿大国家研究委员会赫茨伯格天文学与天体物理研究中心; 太空望远镜科学研究所; 宾夕法尼亚大学; 哈佛-史密森尼天体物理中心; 密歇根大学; 智利大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究联合JWST和HST观测表征了最小TNOs的光学-近红外颜色，发现颜色分布延伸至小尺寸，支持原始起源而非碰撞加工。
AI 中文摘要
我们利用詹姆斯·韦布空间望远镜（JWST）和哈勃空间望远镜（HST）的协调且近乎同步的观测，展示了小型（≤40 km）海王星外天体（TNOs）的光学-近红外（NIR）颜色测量结果。JWST/NIRCam数据提供了对暗弱TNOs的探测和近红外测光，而HST/ACS和WFC3成像则实现了光学波段的恢复，共同产生了覆盖0.35-3.2 μm的光学-近红外颜色。在HST观测中恢复了13个JWST探测到的TNOs，并利用拖尾点扩散函数测光推导了平均星等、颜色和旋转光变曲线。我们新发现的小型冷经典TNOs的颜色分布狭窄，与先前识别出的较大冷经典TNOs所占据的单一反射率（颜色）序列一致。我们未发现该序列在更小尺寸下发生变化的证据。相比之下，我们发现的动力学激发TNOs表现出更宽的颜色范围，与在较大尺寸下看到的多种成分类别一致。我们样本中两个动力学群的光变曲线振幅普遍较低。2015 GK56，一个我们视场中先前已知的TNO，显示出大振幅、结构化的光变曲线，与接触双星一致。我们的结果表明，TNOs的特征颜色分布延伸到了比先前研究更小的尺寸，暗示其起源于原始过程，而非依赖于尺寸的碰撞加工。
英文摘要
We present optical-near-infrared (NIR) color measurements for small ($\leq 40$ km) Trans-Neptunian Objects (TNOs) using coordinated and nearly simultaneous observations from the James Webb Space Telescope (JWST) and the Hubble Space Telescope (HST). JWST/NIRCam data provided detections and NIR photometry for faint TNOs, while HST/ACS and WFC3 imaging enabled recovery in the optical, together yielding optical-NIR colors spanning 0.35-3.2 $μ$m. Thirteen JWST-detected TNOs were recovered in the HST observations, and trailed PSF photometry was used to derive mean magnitudes, colors, and rotational lightcurves. The color distribution of our small cold classical TNO discoveries is narrow and consistent with the occupation of a single reflectance (color) sequence previously identified for larger cold classical TNOs. We find no evidence for a change in this sequence at smaller sizes. In contrast, the dynamically excited TNOs we discovered exhibit a broader range of colors consistent with multiple compositional classes seen at larger sizes. Lightcurve amplitudes were generally low for both dynamical groups in our sample. 2015 GK56, a previously known TNO in our field, displays a large-amplitude, structured lightcurve consistent with a contact binary. Our results indicate that the characteristic color distribution of TNOs extends to smaller sizes than previously studied, suggesting a primordial origin rather than size-dependent collisional processing.
CommentsA machine-readable version of Table 2 is available with the online version of the published article
Journal refAJ 172 (2026) 188
