《自然》20250717出版一周论文导读

 

编译|李言

Nature,17 July 2025,Volume 643 Issue 8072 

《自然》，2025年7月17日，第643卷，8072期

天文学Astronomy

Close-in planet induces flares on its host star

近距离行星在主星上引起耀斑

▲ 作者：Ekaterina Ilin, Harish K. Vedantham et al.

▲链接：

https://www.nature.com/articles/s41586-025-09236-z

▲摘要：

该研究报道了拥有两颗已知近轨行星的1700万年的G型矮星在HIP 67522恒星上探测到的行星诱发耀斑现象。

通过结合凌日系外行星巡天卫星的太空光度测量数据及特征化系外行星望远镜历时5年的专项观测，发现该恒星的15次耀斑爆发最内层行星凌日相位附近集中出现，表明该系统中存在持续的磁星—行星相互作用。这种相互作用的稳定性意味着，最内层行星持续承受着比没有相互作用时高出六倍的耀斑速率。

随后，高能辐射与粒子流持续轰击HIP 67522 b行星，这可能解释了詹姆斯·韦伯太空望远镜近期探测到的该行星大气层的异常膨胀。因此，HIP 67522系统堪称研究磁星—行星相互作用对新生系外行星大气影响的典型范例。

▲ Abstract：

Here we report the detection of planet-induced flares on HIP 67522, a 17 million-year-old G dwarf star with two known close-in planets. Combining space-borne photometry from the Transiting Exoplanet Survey Satellite and dedicated Characterising Exoplanets Telescope observations over 5?years, we find that the 15 flares in HIP 67522 cluster near the transit phase of the innermost planet, indicating persistent magnetic star–planet interaction in the system. The stability of interaction implies that the innermost planet is continuously self-inflicting a six times higher flare rate than it would experience without interaction. The subsequent flux of energetic radiation and particles bombarding HIP 67522 b may explain the remarkably extended atmosphere of the planet, recently detected with the James Webb Space Telescope. HIP 67522 is, therefore, an archetype to understand the impact of magnetic star–planet interaction on the atmospheres of nascent exoplanets.

Refractory solid condensation detected in an embedded protoplanetary disk

在原行星盘内部探测到难熔固态物质凝结

▲ 作者：M. K. McClure, Merel van’t Hoff et al.

▲链接：

https://www.nature.com/articles/s41586-025-09163-z

▲摘要：

研究首次观测到行星系统诞生的'零时刻'，捕捉到一个新生行星系统诞生的初始状态。

通过詹姆斯·韦伯太空望远镜和阿塔卡马大型毫米波阵列对年轻原恒星HOPS-315进行红外与毫米波联合观测，研究发现其2.2天文单位内的星盘大气层底部存在温暖的氧化硅气体与结晶硅酸盐矿物储层，该区域与毫米波观测到的氧化硅喷流在空间上完全隔离。

通过与快速颗粒生长凝结模型及星盘结构模型的对比，表明此处形成的难熔固态物质与太阳系内同类物质具有相似性。研究结果表明，星盘内缘区域的物质环境受到星际固态物质升华作用支配，随后从该气体储层中再凝结形成的难熔固体物质，其时间尺度与太阳系内难熔物质凝结过程相当。

▲ Abstract：

Here we report the astronomical detection of this t?=?0 moment, capturing the building blocks of a new planetary system beginning its assembly. The young protostar HOPS-315 is observed at infrared and millimetre wavelengths with the James Webb Space Telescope (JWST) and the Atacama Large Millimeter Array (ALMA), revealing a reservoir of warm silicon monoxide gas and crystalline silicate minerals low in the atmosphere of a disk within 2.2?AU of the star, physically isolated from the millimetre SiO jet. Comparison with condensation models with rapid grain growth and disk structure models suggests the formation of refractory solids analogous to those in our Solar System. Our results indicate that the environment in the inner disk region is influenced by sublimation of interstellar solids and subsequent refractory solid recondensation from this gas reservoir on timescales comparable with refractory condensation in our own Solar System.

化学Chemistry

Electricity-driven enzymatic dynamic kinetic oxidation

电驱动酶的动态动力学氧化

▲ 作者：Beibei Zhao, Yuanyuan Xu et al.

▲链接：

https://www.nature.com/articles/s41586-025-09178-6

▲摘要：

该研究用二茂铁介导的电催化重塑硫胺素依赖酶，实现了α-支化醛的非天然动态动力学氧化。这种强大的电酶催化方法能低至0.05 mol%的酶负载量在全细胞体系中应用，并高效合成多种生物活性（S）-脯氨酸，对映体过量值高达99%。

机理研究表明，该电酶系统具有精确底物识别、加速外消旋化以及促进动力学匹配的电子转移过程的多重功能。

▲ Abstract：

Here we report the reshaping of thiamine-dependent enzymes with ferrocene-mediated electrocatalysis to unlock an unnatural dynamic kinetic oxidation of α-branched aldehydes. This robust electroenzymatic approach yields various bioactive (S)-profens with up to 99% enantiomeric excess; it is applicable with whole cells overexpressing the enzyme and using down to 0.05?mol% enzyme loadings. Mechanistic investigations show multiple functions of the electroenzyme in precise substrate discrimination, accelerating racemization and facilitating kinetically matched electron transfer events.

地球科学Earth Science

Global terrestrial nitrogen fixation and its modification by agriculture

全球陆地生态系统氮固定及其农业活动影响

▲ 作者：Carla R. Reis Ely, Steven S. Perakis et al.

▲链接：

https://www.nature.com/articles/s41586-025-09201-w

▲摘要：

研究揭示了不确定性部分源于采样偏差——现有自然陆地生态系统的生物固氮（BNF）测量数据多来自固氮生物丰度达全球平均水平17倍的区域。为校正偏差，研究人员通过空间显式尺度转换方法，基于主要生物地球化学固氮生态位分布对实地测量数据进行升尺度估算，获得全球陆地BNF新估值。

研究发现自然生物群落的BNF总量为65?(52–77)?Tg?N?yr