X-ray bursts have recently been discovered in the Cepheids δ Cep and β Dor modulated by the pulsation cycle. We have obtained an observation of the Cepheid η Aql with the XMM-Newton satellite at the phase of maximum radius; the phase at which there is a burst of X-rays in δ Cep. No X-rays were seen from the Cepheid η Aql at this phase, and the implications for Cepheid upper atmospheres are discussed. We have also used the combination of X-ray sources, as well as Gaia and 2MASS data, to search for a possible grouping around the young intermediate mass Cepheid. No indication of such a group was found.

中文翻译：

---

造父变星中的 X 射线：η Aql 的 XMM-牛顿观测基于 XMM-牛顿观测，这是一项欧空局科学任务，其仪器和捐款由欧空局成员国和美国 (NASA) 直接资助。

最近在由脉动周期调制的造父变星δ Cep 和β Dor 中发现了 X 射线爆发。我们已经获得了Cepheid公司的观察η AQL在最大半径的相位XMM牛顿卫星; δ Cep 中爆发 X 射线的相位。在这个阶段没有从造父变星η Aql看到 X 射线，并讨论了对造父变星高层大气的影响。我们还使用了 X 射线源以及盖亚和 2MASS 数据的组合，以寻找围绕年轻中间质量造父变星的可能分组。没有发现此类团体的迹象。