AI 中文总结
研究通过詹姆斯·韦布空间望远镜近红外相机日冕仪成像，对绘架座β b进行光度监测，用开发的时间序列光度测量框架，发现其光度呈正弦变化，得出自转周期等，为其形成方式提供证据，开启了对这类行星相关研究的新窗口。
AI 中文摘要
我们报告了在直接成像的超级木星绘架座β b中检测到光度变化。利用詹姆斯·韦布空间望远镜近红外相机双波段日冕仪成像，我们在F210M和F410M滤镜下进行了16小时的连续光度监测活动。我们开发并验证了一个时间序列光度测量框架，该框架结合了点扩散函数减法、用于去除系统噪声的主成分分析以及注入和恢复测试以确认信号保真度。两条光变曲线分别在F210M和F410M波段显示出约5σ和远大于5σ显著性的一致正弦变化。联合正弦拟合得出自转周期\(P_{\rm rot}=9.00\pm0.13\)小时，F210M和F410M波段的变化幅度分别为\(0.85\pm0.07\%\)和\(0.89\pm0.04\%\)。两个波段几乎相同的幅度和周期证实了在非均匀大气中有共同的天体物理起源。结合\(P_{\rm rot}\)与先前测量的投影自转速，我们限制了绘架座β b的视线自旋轴倾角。结果支持赤道面观测几何，与视线自旋 - 轨道对齐一致：行星自旋轴、轨道平面、碎片盘和恒星赤道都相互对齐。这与可能通过引力碎裂形成的宽分离伴星的大倾角形成鲜明对比。结合该系统的年轻年龄，这一观测提供了独立的动力学证据，表明绘架座β b是通过核心吸积形成的。这一结果构成了对可能通过核心吸积形成的近距离、高对比度系外行星旋转调制的首次探测，表明利用詹姆斯·韦布空间望远镜进行的时间序列日冕仪成像为这类行星的自转、大气动力学和自旋 - 轨道结构打开了一个强大的新窗口。
英文摘要
We report the detection of photometric variability in the directly imaged super-Jupiter $β$ Pictoris b. Using JWST NIRCam dual-band coronagraphic imaging, we conducted a 16-hour continuous photometric monitoring campaign in the F210M and F410M filters. We developed and validated a time-series photometry framework that combines PSF subtraction, principal component analysis for systematic noise removal, and injection-and-recovery tests to confirm signal fidelity. Both light curves show consistent sinusoidal variability at $\sim$5$σ$ and $\gg 5σ$ significance in the F210M and F410M bands, respectively. A joint sinusoidal fit yields a rotation period of $P_{\rm rot} = 9.00 \pm 0.13$ hr and variability amplitudes of $0.85 \pm 0.07\%$ and $0.89 \pm 0.04\%$ in F210M and F410M, respectively. The near-identical amplitudes and periods in both bands confirm a common astrophysical origin in a heterogeneous atmosphere. Combining $P_{\rm rot}$ with the previously measured projected rotational velocity, we constrain the line-of-sight spin axis inclination of $β$ Pic b. The result favors an equator-on viewing geometry, consistent with line-of-sight spin-orbit alignment: the planetary spin axis, orbital plane, debris disk, and stellar equator are all mutually aligned. This stands in sharp contrast to the large obliquities of wide-separation companions that are likely formed via gravitational fragmentation. Together with the system's young age, this observation provides independent dynamical evidence that $β$ Pic b formed via core accretion. This result constitutes the first detection of rotational modulation in a close-in, high-contrast exoplanet that likely formed via core accretion, demonstrating that time-series coronagraphic imaging with JWST opens a powerful new window onto the rotation, atmospheric dynamics, and spin-orbit architecture of this population.
Comments26 pages, 18 figures. Accepted for publication in the AAS Journals
