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Moon and Antares

February 14, 2012

Anyone who’s ever been outshined by a flashy sibling can sympathize with the star known as Antares B. The star is quite impressive — it’s much bigger, heavier, and brighter than the Sun. In fact, it’s among the top one or two percent of all the stars in the galaxy in each of those categories.

Yet Antares B is completely outclassed by a sibling, Antares A. It outranks Antares B in every category, and it’s one of the brightest stars in the night sky, even though it’s hundreds of light-years away. Antares B is lost in the glare — you need a telescope to see it as a separate star.

Antares A is a supergiant — one of the most massive stars in the galaxy. And it will end its life as a supernova — a titanic explosion that will rip the star to bits, leaving only a crushed remnant known as a neutron star.

Antares B probably isn’t quite massive enough to create a supernova. Instead, it’ll end its life just as our Sun will — as a white dwarf. It will cast its outer layers into space, but in a much gentler process than a supernova. Its core will be crushed to form a ball about as big as Earth. It won’t be nearly as heavy or as dense as a neutron star, though — just one more way in which Antares B will be outshined by its impressive sibling.

Look for the Antares system standing a little below the Moon at first light tomorrow. It shines bright orange — not surprisingly, the color of Antares A.

Tomorrow: a winter wonderland.


Script by Damond Benningfield, Copyright 2011


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