A space telescope designed to peer into the guts of distant dead stars has swiveled to gaze at one that’s very much alive: The sun.

This first image of the sun from NASA’s NuSTAR telescope, released today, suggests that high energy X-rays tend to cluster near active regions on the solar surface — just not all of them.

NuSTAR’s eyes are sensitive to these high-energy X-rays, which are emitted by the hottest, most energetic astrophysical processes.

In the image above, the bluish-green patches are X-rays detected by NuSTAR that occur near areas where gas has been heated to more than 5 million degrees Fahrenheit. The reddish sun is an ultraviolet image captured by NASA’s Solar Dynamics Observatory, which offers a glimpse of lower-energy, lower-temperature material.