One of the biggest and brightest stars in the night sky will disappear for a moment as an asteroid passes in front of it to cause a unique eclipse.
The rare and fleeting spectacle, late Monday into early Tuesday, should be visible to millions of people along a narrow path that stretches from Tajikistan and Armenia, through Turkey, Greece, Italy and Spain, to Miami and the Florida Keys and finally, to parts of Mexico.
The star is Betelgeuse, a red supergiant in the constellation Orion. The asteroid is Leona, a slowly rotating, elongated 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 an eclipse of a much fainter star by Leona in September, a team led by Spain recently estimated that the asteroid is about 34 miles wide and 50 miles long (55 km wide and 80 km long).
There are lingering uncertainties about those predictions as well as the size of the star and its vast atmosphere. It is unclear whether the asteroid will eclipse the entire star and cause a total eclipse. Instead, the result may be a “ring of fire” eclipse with a tiny burning rim around the star. If it’s a total eclipse, astronomers aren’t sure how many seconds the star will completely disappear, perhaps up to 10 seconds.
“Which scenario we will see is uncertain, which makes the event even more intriguing,” said astronomer Gianluca Masa, founder of the Virtual Telescope Project, which will provide a live webcast from Italy.
An estimated 700 light-years away, Betelgeuse is visible to the naked eye. Binoculars and small telescopes will improve the view. A light year is 5.8 ton miles.
Betelgeuse is thousands of times brighter than our sun and about 700 times larger. It is so large that if it replaced our sun, it would extend beyond Jupiter, according to Nasa.
At just 10m years old, Betelgeuse is significantly younger than the 4.6 billion year old sun. Scientists expect Betelgeuse to be short-lived, given its mass and the speed at which it burns through its material.
After countless centuries of fluctuating brightness, Betelgeuse dimmed dramatically in 2019 as a large mass of surface material was ejected into space. The resulting dust cloud temporarily blocked the starlight, Nasa said, and within half a year Betelgeuse was as bright as before.
Scientists expect Betelgeuse to go supernova in a violent explosion within 100,000 years.
