Mesarthim

Its story

Mesarthim, together with Sheratan, formed in antiquity the 'two signs' that opened the astronomical year as the Sun entered Aries at the spring equinox. In 1664 Robert Hooke observed it almost by chance through a telescope and found it to be a double star — one of the very first binaries identified in the history of astronomy. Its faintly variable white light travels 164 light-years to reach tonight and the eye of the observer.