of 22,200K. It emits a total radiation equal to 38,700 times that of the Sun. This star is the brightest source of extreme ultraviolet in the night sky. It is the strongest source of photons capable of ionizing hydrogen atoms in interstellar gas near the Sun, and is very important in determining the ionization state of the Local Interstellar Cloud. The +7.5-magnitude (the absolute magnitude amounts to +1.9) companion star, ε Canis Majoris B, is 7.5" away with a position angle of 161° of the main star. Despite the relatively large angular distance the components can only be resolved in large telescopes, since the primary is approximately 250 times brighter than its companion. A few million years ago, ε Canis Majoris was much closer to the Sun than it is at present, causing it to be a much brighter star in the night sky. About 4.7 million years ago, Adhara was 34 light-years from the Sun, and was the brightest star in the sky with a magnitude of –3.99. No other star has attained this brightness since, nor will any other star attain this brightness for at least five million years. In culture USS Adhara (AK-71) was a U.S. Navy Crater-class cargo ship named after the star. ε Canis Majoris appears on the national flag of Brazil, symbolising the state of Tocantins. References B-type bright giants Binary stars Canis Major Canis Majoris, Epsilon 2618 CD-28 03666 Canis Majoris, 21 052089 033579 Adhara