December 2019, ScientificAmerican.com 75FIRST LIGHT
CHANDRA’S OFFICIAL first light image, of the iconic supernova remnant Cassiopeia A,
immediately demonstrated the power of the telescope’s high spatial resolution by discovering
the long-sought neutron star at the center of this nebula. The dense neutron star, a remnant
of the much larger star that exploded around 340 years ago as a supernova, had never been
visible before. This image combines Chandra data taken over a period of several years, increas-
ing the visible details of the complex structure. It also uses the observatory’s energy resolution
to reveal different chemical elements that were created within the star and blown out by the
explosion: red color indicates silicon, yellow is sulfur, green shows calcium and purple displays
iron. The bluish outer ring in the image is emission from high-energy particles accelerated in
the forward shock wave of the explosion—another aspect first discovered by Chandra.
NASA, CXC AND SAOMORE TO EXPLORE
Exploring the Extreme: 20 Years of Chandra. Chandra X-ray Center. https://chandra.si.edu/20th
FROM OUR ARCHIVES
Exploring Our Universe and Others. Martin Rees; December 1999.
All the Light There Ever Was. Alberto Domínguez, Joel R. Primack and Trudy E. Bell; ScientificAmerican.com, June 1, 2015.
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