Friday, June 17, 2016


For those of us in the Northern Hemisphere, Antares is one of the brightest stars in the summer sky.  A component of the Constellation Scorpio, it shines from the southern sky; in mid June, it's reddish image can be seen to the SSE at 10 PM and was just below the moon last evening.

Like its winter counterpart, Betelgeuse (in Orion), Antares is a super red giant; if placed at the location of our sun, its outer surface would lie between the orbits of Mars and Jupiter (i.e., the four inner planets of our solar system would be swallowed by its mass).  Antares is about 520 light years from Earth; though it is among the 20 brightest stars in the night sky, it would be far brighter if the majority of its radiation was not in the infra-red spectrum (and thus not visible to the human eye).

Super red giants are stars in the latest stage of their life; when they eventually collapse, a black hole is thought to form and their energy is released as a supernova, spawning the birth of many new stars.  Since Antares is 520 light years away, it may have exploded into a supernova 500 years ago and we won't know until 2036; in other words, the light that arrives from Antares today left the star about the time that Columbus left for the New World.