X-ray astrophysics as secondary science with ESA/China SMILE satellite

We present and discuss the feasibility of X-ray astrophysics with ESA-China SMILE satellite designed to investigate the Earth's magnetosphere's dynamic response to the solar wind's impact. We plan to study celestial X-ray targets as a secondary science for the onboard wide-field X-ray telescope SXI and related Czech participation in this mission. The Solar Wind Magneto-sphere Ionosphere Link Explorer, or SMILE, is a joint mission between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS). We show that SXI can also provide wide-field imaging of the sky in the soft X-ray region (E = 0.15 - 3 keV) and observe the long-term activity of cosmic X-ray sources. We show the stability of the orientation of the field of view of the SXI telescope; it will undergo only minor changes during several years of the planned operation. Therefore, observing the long-term soft X-ray activity of cosmic sources, e.g., those in the Magellanic Clouds, will be possible.