We present images of the Vega planetary debris disk obtained at 15.5, 23, and 25.5 μm with the Mid-Infrared Instrument on JWST. The debris system is remarkably symmetric, smooth, and centered accurately on the star. There is a broad Kuiper-belt-analog ring at ∼80–170 au that coincides with the planetesimal belt detected with the Atacama Large Millimeter/submillimeter Array at 1.34 mm. The interior of the broad belt is filled with warm debris that shines most efficiently at mid-infrared, along with a shallow flux dip/gap at 60 au from the star. These qualitative characteristics argue against any Saturn-mass planets orbiting the star outside of about 10 au, assuming the unseen planet would be embedded in the very broad planetesimal disk from a few to hundreds of astronomical units. We find that the distribution of dust detected interior to the broad outer belt is consistent with grains being dragged inward by the Poynting–Robertson effect. Under the drag-dominated disk assumption, tighter constraints can be derived for planets in specific locations; for example, any planet shepherding the inner edge of the outer belt is likely to be less than six Earth masses. The disk surface brightness profile along with the available infrared photometry suggest a disk inner edge near ∼3−5 au, disconnected from the sub-astronomical-unit region that gives rise to the hot near-infrared excess. The gap between the hot, sub-astronomical-unit zone and the inner edge of the warm debris might be shepherded by a modest-mass, Neptune-size planet.

中文翻译：

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使用 JWST/MIRI 对 Vega 碎片系统进行成像


我们展示了使用 JWST 上的中红外仪器在 15.5、23 和 25.5 μm 处获得的 Vega 行星碎片盘的图像。碎片系统非常对称、光滑，并且准确地以恒星为中心。在 ∼80-170 au 处有一个宽阔的柯伊伯带模拟环，与阿塔卡马大型毫米/亚毫米阵列在 1.34 毫米处探测到的小行星带重合。宽阔的带内部充满了温暖的碎片，这些碎片在中红外处最有效地发光，以及距离恒星 60 au 的浅通量下降/间隙。这些定性特征反对任何围绕恒星运行超过 10 天文单位的土星质量行星，假设这颗看不见的行星会嵌入到非常宽的行星盘中，从几个天文单位到数百个天文单位。我们发现，检测到的尘埃内部到宽阔的外带的分布与颗粒被坡印廷-罗伯逊效应向内拖动是一致的。在阻力主导的盘假设下，可以为特定位置的行星推导出更严格的约束;例如，任何位于外带内边缘的行星都可能小于 6 个地球质量。圆盘表面亮度剖面以及可用的红外光度法表明，圆盘内边缘接近 ∼3-5 au，与产生热近红外过剩的亚天文单位区域断开。炽热的亚天文单位区和温暖碎片的内缘之间的间隙可能被一颗中等质量、海王星大小的行星所覆盖。