We report JWST Mid-Infrared Instrument (MIRI) Medium Resolution Spectrograph (MRS) observations of the β Pic moving-group member, η Tel A, along with its brown dwarf binary companion, η Tel B. Following point-spread-function subtraction, we recover the spatially resolved flux from the debris disk around η Tel A, along with the position of the companion exterior to the disk. We present a new 5–26 μm epoch of spectroscopy for the disk, in which we discover a 20 μm silicate feature, and the first ever 11–21 μm spectrum of η Tel B, which indicates a bare photosphere. We derive a new epoch of relative astrometry for the companion, extending the baseline of measurements to 25 yr, and find that it is currently located near the apocenter of an eccentric long-period orbit. The companion’s orbit is close enough to the disk that it should significantly perturb the planetesimals within it, resulting in a detectable mid-IR pericenter glow and near alignment with the companion. Contrary to expectations, however, we find that the disk appears to be axisymmetric and potentially misaligned with the companion in the MIRI MRS data. We posit that this may be due to the presence of an additional, as-yet-undetected ∼0.7–30 MJ planet orbiting interior to the disk, with a semimajor axis of ∼3–19 au.

中文翻译：

---

JWST MIRI MRS η Tel 碎片盘及其棕矮星伴星的视图


我们报告了 JWST 中红外仪器 （MIRI） 中分辨率光谱仪 （MRS） 对 β Pic 移动群成员 η Tel A 及其褐矮星双星伴星 η Tel B 的观测。在点扩散函数减去之后，我们从 Tel A 周围的碎片盘中恢复η空间分辨通量，以及盘外部伴星的位置。我们提出了一个新的 5-26 μm 圆盘光谱学时期，其中我们发现了 20 μm 的硅酸盐特征，以及有史以来第一个 11-21 μm 的 η Tel B 光谱，这表明一个裸露的光球层。我们推导出了伴星的相对天体测量的新纪元，将测量基线扩展到 25 年，发现它目前位于偏心长周期轨道的远心附近。伴星的轨道离圆盘足够近，它应该会显著扰动其中的行星体，从而产生可探测的中红外近心发光，并与伴星近乎对齐。然而，与预期相反，我们发现磁盘似乎是轴对称的，并且可能与 MIRI MRS 数据中的伴星错位。我们假设这可能是由于存在一颗额外的、尚未检测到的 ∼0.7-30 MJ 行星，它围绕盘内部运行，其半长轴为 ∼3-19 au。