Of course, as beautiful as it is, this picture of Cassiopeia A is in false color. This is what happens after a supernova explodes, the beautiful remains are still seen after 325 years. This once massive star met its match and is now a cloud of gas surrounding what is left of the core, the tiny teal dot in the center. This leftover core is called a neutron star.
10,000 light-years away, this sits in the Cassiopeia constellation, one you might see in the sky. In this photo we see a collage of different telescope images from three of NASA’s Great Observatories: infrared data from the Spitzer Space Telescope are colored red; data from the Hubble Space Telescope are yellow; and X-ray data from the Chandra X-ray Observatory are green and blue.
You can find more information here: https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA03519