Powerful, Pulsating Core of Star: Our Milky Way galaxy is littered with the still-sizzling remains of exploded stars. The blue dot in this image marks the spot of an energetic pulsar -- the magnetic, spinning core of star that blew up in a supernova explosion. We discovered the pulsar by identifying its telltale pulse -- a rotating beam of X-rays, that like a cosmic lighthouse, intersects Earth every 0.2 seconds. The pulsar lies in our inner Milky Way galaxy about 42,000 light-years away. Image credit: NASA/JPL-Caltech/SAO #nustar #nasa #space #astronomy #galaxy #star #xray #milkyway #science