The surface temperature of Canopus is 7350 ± 30 K. Its diameter has been measured at 0.6 astronomical units (the measured angular diameter being 0.006 arcseconds), 65 times that of the Sun. If it were placed at the centre of the solar system, it would extend three-quarters of the way to Mercury. An Earth-like planet would have to lie three times the distance of Pluto for its star to appear the same size in the sky as our own sun. Canopus is a strong source of X-rays, which are probably produced by its corona, magnetically heated to around 15 million K.