CAPE CANAVERAL, Fla. – One of the biggest and brightest stars in the night sky will disappear momentarily when an asteroid passes in front of it to produce a unique eclipse.
Late Monday through early Tuesday, this rare and fleeting spectacle is supposed to be visible to millions of people along a narrow route that extends from Tajikistan and Armenia in Central Asia, through Turkey, Greece, Italy and Spain, to Miami and the Florida Keys and finally, to… Parts of Mexico.
The star is Betelgeuse, a massive red giant located in the constellation Orion. The asteroid is Leona, a slowly rotating rectangular space rock in the main asteroid belt between Mars and Jupiter.
Astronomers hope to learn more about Betelgeuse and Leona through the eclipse, which is expected to last no more than 15 seconds. By observing the eclipse of a star much dimmer than Leona in September, a Spanish-led team recently estimated that the asteroid is about 34 miles across and 50 miles long (55 kilometers wide and 80 kilometers long).
There are lingering uncertainties about those predictions as well as the star’s size and extended atmosphere. It is unclear whether the asteroid will obscure the entire star, causing a total eclipse. Alternatively, the result could be a “ring of fire”-shaped eclipse with small flaming boundaries around the star. If the eclipse is total, astronomers are not sure how many seconds the star will disappear completely, perhaps as low as 10 seconds.
“The scenario we will see is uncertain, which makes the event even more interesting,” said astronomer Gianluca Massa, founder of the Virtual Telescope Project, which will provide a live online broadcast from Italy.
About 700 light-years away, Betelgeuse can be seen with the naked eye. Binoculars and small telescopes will enhance viewing. A light year equals 5.8 trillion miles.
Betelgeuse is thousands of times brighter than our Sun and about 700 times larger. It is so massive that if it replaced our Sun, it would extend beyond Jupiter, according to NASA.
Betelgeuse is only 10 million years old, much younger than the Sun’s 4.6 billion years. Scientists expect Betelgeuse to be short-lived, given its mass and the speed at which its matter burns up.
After countless centuries of varying brightness, Betelgeuse’s star dimmed dramatically in 2019 when a huge swath of surface material was ejected into space. The resulting dust cloud temporarily blocked starlight, and within half a year, Betelgeuse was as bright as before, NASA said.
Scientists expect that Betelgeuse will turn into a supernova in a violent explosion within 100,000 years.
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