Finishing touches to the Einstein Probe’s Follow-up Telescope

In this photo, taken in May 2023, a team of engineers at the Institute of High-Energy Physics of the Chinese Academy of Sciences (CAS) is finalising the construction of the Follow-up X-ray Telescope (FXT) for the Einstein Probe mission.

Einstein Probe is a collaboration led by CAS with the European Space Agency (ESA) and the Max Planck Institute for Extraterrestrial Physics (MPE), Germany. This is a very innovative mission, designed to continuously monitor the X-ray sky and hunt for powerful blasts of X-ray light coming from mysterious celestial objects such as neutron stars and black holes.

For this, Einstein Probe carries two advanced instruments: the Wide-field X-ray Telescope (WXT) to monitor extremely large areas of the X-ray sky in one shot, and the Follow-up X-ray Telescope (FXT) to swiftly observe with more sensitivity the new sources spotted by WXT.

As seen from the image, FXT consists of two X-ray telescopes. The optics of each unit follow a classic Wolter-I design with a mirror assembly based on the technology first developed for ESA’s XMM-Newton.