AI 中文总结
该研究通过VLT/SPHERE对13颗行星和褐矮星进行观测，获取其光度测量和天体测量数据，结合文献数据得出更新轨道解，还获得光谱，新数据表明其光谱类型及轨道特性，对行星形成范式研究有重要意义。
AI 中文摘要
在过去十年中，高对比度成像仪器与极端自适应光学系统的进步，使人们发现了数十颗在与其主恒星相距很远（大于10天文单位）的轨道上运行的行星和褐矮星。这些距离上伴星的存在对当前行星形成范式提出了挑战，凸显了高对比度成像作为唯一能够直接探测行星系统这一区域的技术的重要性。本文展示了对2023年6月至2025年7月期间用VLT/SPHERE观测的13颗行星和褐矮星的调查。这些数据提供了1.0 - 1.7微米范围内的更新光度测量和新的高精度天体测量，能更严格地限制它们的轨道特性。使用IRDIS子系统获取样本中所有伴星的双波段H2H3图像（H2 = 1.593微米，H3 = 1.667微米）。对于位于IFS视场内的三个天体，还获得了低分辨率（R ~ 50）近红外（0.96 - 1.34微米）光谱。将新的天体测量数据与文献中的数据结合以得出更新的轨道解，使用orbitize! Python包进行轨道拟合。对于CT Cha b、HIP 78530 B、HIP 64892 B和RX J1609.5 - 2105 b，这项工作提供了迄今为止的首个轨道解。得出了所有天体的新光度测量数据，与颜色 - 星等图中的场矮星相比，表明其光谱类型从中型M到中型L。对于用IFS观测的伴星，其光谱与M6 - M8.5场矮星的光谱最匹配。更新后的轨道拟合为几乎所有伴星提供了更严格的限制，并且在所有情况下都与非圆形轨道一致，这可能不利于它们的星周盘中的核心吸积形成。
英文摘要
Over the past decade, advances in high-contrast imaging instrumentation, coupled with extreme adaptive optics systems, have enabled the discovery of tens of planets and brown dwarfs orbiting at wide separations from their host stars (a larger than 10 au). The existence of companions at these separations challenges current planet-formation paradigms, highlighting the importance of high-contrast imaging as the only technique capable of directly probing this region of planetary systems. In this paper, we present a survey of thirteen planets and brown dwarfs observed with VLT/SPHERE between June 2023 and July 2025. These data provide updated photometry in the 1.0-1.7 micron range and new high-precision astrometry, enabling tighter constraints on their orbital properties. We used the IRDIS subsystem to acquire dual-band H2H3 images (H2 = 1.593 microns, H3 = 1.667 microns) for all companions in our sample. For the three objects located within the IFS field of view (GQ Lup B, PZ Tel B, and HD 984 B), we additionally obtained low-resolution (R ~ 50) near-infrared (0.96-1.34 micron) spectra. We combined our new astrometric measurements with those available in the literature to derive updated orbital solutions. The orbital fitting was performed using the orbitize! Python package. For CT Cha b, HIP 78530 B, HIP 64892 B, and RX J1609.5-2105 b, this work provides the first orbital solutions to date. We derived new photometry for all objects, which, when compared with field dwarfs in color-magnitude diagrams, indicates spectral types ranging from mid-M to mid-L. For the companions observed with IFS, their spectra are best matched by those of M6-M8.5 field dwarfs. Our updated orbital fits provide tighter constraints for nearly all companions and are consistent with non-circular orbits in all cases, potentially disfavoring core-accretion formation within their circumstellar disks.
DOI：10.1051/0004-6361/202558743
