A planetary collision afterglow and transit of the resultant debris cloud.
A planetary collision afterglow and transit of the resultant debris cloud.
复制标题
行星碰撞余辉和由此产生的碎片云的传输。
DOI：
10.1038/s41586-023-06573-9
复制
发表时间：
2023
期刊：
影响因子：
64.8
通讯作者：
Kenworthy M
中科院分区：
文献类型：
--
作者：
Kenworthy M
行星在形成恒星周围的旋转尘埃和气体盘中生长，其中一些气体成分从盘中去除后，随后会在巨大的撞击中发生碰撞。温暖的斯皮策任务的监测项目记录了几颗恒星中红外输出的显着而快速的变化，解释为由行星尺度碰撞喷射并被中心恒星加热的温暖尘埃物质表面积的变化：例如，NGC 2354–ID8（参考文献）、HD 166191（参考文献 ）和英仙座V488。在这里，我们报告了对年轻（约 3 亿岁）类太阳恒星 ASASSN-21qj 的综合观测：红外增亮与 1,000 开尔文的黑体温度一致，光度为该恒星的 4%，持续约 1,000 天，与持续约 1,000 天的复杂而深刻、与波长相关的日食部分重叠。 500天。日食在红外增亮后 2.5 年开始，这意味着轨道周期至少有这个持续时间。这些观测结果与两颗质量为数到数十倍地球的系外行星在距离中心恒星 2-16 个天文单位处发生的碰撞一致。这种撞击会产生炽热、高度延伸的撞击后残余物，其亮度足以解释红外观测结果。撞击碎片被轨道运动剪切成长云，导致主星随后发生复杂的日食。
Planets grow in rotating disks of dust and gas around forming stars, some of which can subsequently collide in giant impacts after the gas component is removed from the disk, –. Monitoring programmes with the warm Spitzer mission have recorded substantial and rapid changes in mid-infrared output for several stars, interpreted as variations in the surface area of warm, dusty material ejected by planetary-scale collisions and heated by the central star: for example, NGC 2354–ID8 (refs.,), HD 166191 (ref. ) and V488 Persei. Here we report combined observations of the young (about 300 million years old), solar-like star ASASSN-21qj: an infrared brightening consistent with a blackbody temperature of 1,000 Kelvin and a luminosity that is 4 percent that of the star lasting for about 1,000 days, partially overlapping in time with a complex and deep, wavelength-dependent optical eclipse that lasted for about 500 days. The optical eclipse started 2.5 years after the infrared brightening, implying an orbital period of at least that duration. These observations are consistent with a collision between two exoplanets of several to tens of Earth masses at 2–16 astronomical units from the central star. Such an impact produces a hot, highly extended post-impact remnant with sufficient luminosity to explain the infrared observations. Transit of the impact debris, sheared by orbital motion into a long cloud, causes the subsequent complex eclipse of the host star.