Ford Prefect researcher for ‘The Hitchhiker’s Guide to the Galaxy‘,from a small planet in the vicinity of Betelgeuse,in the constellation Orion, may well have missed the greatest cosmic light show in 1000 Earth years.
Betelgeuse is designated as ‘Alpha’ which are typically the brightest in their constellations. Although this giant star is fainter than Orion’s other celestial beacon, Rigel. Betelgeuse is the 10th brightest star in the sky overall, and it’s the 7th brightest star visible from most of Europe, and the majority of the northern hemisphere. If you go outside and take a look at the constellation Orion, it’s his right shoulder, located at the upper left corner of the large rectangle forming Orion.
Its orange-red glow is quite distinctive. At mid-northern latitudes around the first of the year, Betelgeuse rises around sunset. By the beginning of March it is due south at early evening, and by mid-May it can be glimpsed briefly in the west after sunset. Betelgeuse is traveling behind the sun in early summer, but it returns to the east before dawn by about mid-July.
That might not look like much, but it is. Viewed from earth’s largest telescopes we can see sunspots on it! It is about 1000 times the diameter of the sun. If you took Betelgeuse and overlaid it on the Sun, the outer edge of the star would be somewhere out by the orbit of Saturn. It is the ninth known -largest star in our universe.
It is some 8.5 million years old. This red supergiant has already burned up its supply of hydrogen, and is currently burning helium and heavier elements, working its way up to iron. Once iron starts building up there’s no more internal outward pressure to counter gravitational collapse, and when that happens – BOOM – a Type II Supernova, with a neutron star or black hole left over.
The supergiant, Betelgeuse is an excellent candidate for a supernova at some time “within the next few thousand years.” More gravitational pressure means the fusion reaction runs at a higher rate, so the most massive super giants can burn through their hydrogen in under a million years. Betelgeuse has been shrinking since 1993 and has lost 15% of its mass since then and that process continues to accelerateThat shrinkage points to a theory that the star isn’t there anymore. It is likely that the time frame of "within the next few thousand years" has changed to "within the next few years, months….. ..or weeks.When it explodes,it will be spectacular; the best-observed supernova in history occurred in 1054, which was visible, in broad daylight, for 23 days, and at night for almost two years. That star was 6300 light years away. Betelgeuse is approximately 400 light years away.So the light,that left the star in the late 1500’s, could be twice as bright as that of a full moon.The era after Copernicus, on his deathbed, published his great heliocentric theory, suggesting that the sun – not the Earth – resides in the center of the cosmos. Yet it was before Galileo became the first scientist to turn his newly invented telescope to the heavens in the early 1600s.
Who knows when this celestial firework will be visible? Perhaps on 21st December 2012. ?