Fig11_11 Cassiopeia A_radio VLA image

Fig11_11 Cassiopeia A_radio VLA image

Fig. 11.11 . This Type II supernova remnant is the brightest radio source in the sky, other than the Sun, and is designated 3C 461 from its number in the third Cambridge catalogue of bright radio objects. It is also known as Cassiopeia A, the most intense radio source in the direction of the constellation of Cassiopeia. Also called Cas A for short, it is the remnant of a supernova explosion that occurred about 1680, or roughly 330 years ago as observed from Earth, at a distance of about 10,000 light-years. It has a radius of about 8.6 light-years and is expanding at a velocity of roughly 5,000 km s-1. (A VLA image courtesy of NRAO/AUI.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University