发表机构
Northwestern University; University of Arizona; University of Maryland, Baltimore County; NASA-GSFC; Space Telescope Science Institute (STScI)（西北大学; 亚利桑那大学; 马里兰大学巴尔的摩分校; 美国宇航局戈达德太空飞行中心; 空间望远镜科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过JWST和LBTI直接成像，在年轻M矮星RX J0534周围发现巨行星RX J0534 b（约2.8木星质量）及碎片盘，为M矮星行星形成提供关键观测约束。
AI 中文摘要
我们报道了RX J0534.0-0221 b的发现，这是一颗围绕β Pictoris移动群中M矮星运行的巨行星。RX J0534最初使用JWST/NIRCam在F444W和F200W滤光片下进行观测。F444W观测揭示了一个信噪比约为17.5的点源，位于距主星约0.41角秒（约14天文单位）处，而在F200W中未探测到该源。使用LBTI/LMIRCam在L'波段的后续观测在JWST观测后16个月重新探测到该源，提供了共同自行运动的证据，排除了与背景天体偶然对齐的可能性，置信度为6-7σ。对可用测光数据的大气网格模型拟合得出热光度log10(L/L☉) = -5.48(+0.10/-0.19) dex。在18-26百万年的年龄下，热启动演化模型预测质量M = 2.8(+0.5/-0.5) 木星质量，有效温度Teff = 674(+57/-49) K。根据L'-F444W颜色和星等，我们发现了行星大气中非平衡化学或增强金属丰度的证据。此外，在JWST F200W观测中探测到一个延展结构，与一个已分辨的碎片盘一致，其峰值密度半径为79(+3/-3) 天文单位，倾角为56.5(+1.5/-1.5) 度。RX J0534 b是迄今成像的最低质量行星之一。继TWA 7 b之后，它是第二颗围绕M矮星在太阳系尺度轨道上成像的行星（第一颗在50天文单位以内），也是第一颗通过共同自行运动确认的此类行星。未来的轨道监测和大气表征将揭示其形成历史，考虑到M矮星周围巨行星形成的挑战性，这是一个特别有趣的问题。
英文摘要
We present the discovery of RX J0534.0-0221 b, a giant planet orbiting an M-dwarf star in the $β$ Pictoris moving group. RX J0534 was originally observed with JWST/NIRCam in the F444W and F200W filters. Observations in F444W reveal a point source at signal-to-noise ratio $\sim17.5$ at $\sim0.41$ arcsec ($\sim14$ au) from the host star, with no detection of the source in F200W. A follow-up observation with LBTI/LMIRCam in $L'$ band re-detects the source 16 months after the JWST epoch, providing evidence for common proper motion over a chance alignment with a background interloper at the $6-7σ$ level. Atmospheric grid model fits to the available photometry yield bolometric luminosity log$_{10}(L/L_\odot) = -5.48^{+0.10}_{-0.19}$ dex. At an age of $18-26$ Myr, hot-start evolutionary models predict $M=2.8^{+0.5}_{-0.5}$ M$_{\text{Jup}}$ and $T_{\text{eff}}=674^{+57}_{-49}$ K. From the $L'-F444W$ color and magnitudes we find evidence for disequilibrium chemistry or enhanced metallicity in the planet atmosphere. Additionally, an extended structure is detected in the JWST F200W observation, consistent with a resolved debris disk with peak density radius of $79^{+3}_{-3}$ au and an inclination of $56.5^{+1.5}_{-1.5}$ deg. RX J0534 b is one of the lowest-mass planets imaged to date. After TWA 7 b, it is the second imaged planet around an M-dwarf orbiting at Solar System scales (the first within 50 au), and the first to be confirmed via common proper motion. Future orbital monitoring and atmospheric characterization will shed light on its formation history, a particularly interesting question given the challenging nature of giant planet formation around M-dwarfs.
Comments32 pages, 12 figures. Accepted for publication at ApJL
