Garnet Star (Mu Cephei)
Even at its great (uncertain) distance, Mu Cephei is big enough to show a measurable angular diameter, of around 0.02", equivalent to about 15 AU across. This means that if put in place of the Sun, it would extend midway between the orbits of Jupiter and Saturn.
As is the case with most huge supergiants, the Garnet Star is variable, wobbling in brightness by over a magnitude in a somewhat irregular way over a period of 2 to 2.5 years. The average magnitude varies over a period of a decade or so and dips as low as fifth magnitude. At the same time it is losing mass through a strong wind.
Although the Garnet has certainly stopped internal hydrogen fusion, its exact evolutionary status is uncertain. Most likely, it is fusing helium in its core into carbon. Whatever the conditions, this great star is almost certainly destined to explode as a supernova.
Related category NOTABLE STARS
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact