One of the brightest stars in the night sky will DISAPPEAR for 7 seconds tonight – how to see the once-in-a-lifetime event

Stargazers have a once-in-a-lifetime opportunity to see a rare astronomical event tonight.

But you'll have to be awake during the wee hours of the night to witness it — and if you blink, you might really miss it.

An asteroid known as 319 Leona is set to pass in front of a distant star called Betelgeuse, known for its bright red color and unpredictable behavior.

This so-called “occultation” will cause the star to briefly disappear, as if it had been erased from the night sky, before suddenly reappearing.

The event will occur shortly after 1 a.m. UTC, in the early hours of Tuesday (December 12), but whether or not you'll see it depends on where you are in the world.

Astrophysicist Miguel Montargis at the Paris Observatory described the “exceptional” event as a “once-in-a-lifetime opportunity.”

The event will only be visible along a narrow path (known as an occultation path) that passes through parts of Asia, southern Europe and southern parts of North America – but not the UK.

Dr Robert Massey of the Royal Astronomical Society told MailOnline: 'The asteroid (Leona) will appear to be moving from west to east in the sky, and for Northern Hemisphere observers this means from right to left.'

He added: “It will not be visible from the UK – in Europe, the occultation path extends across the Mediterranean, including southern Italy, southern Spain and southern Portugal, as well as Florida and Mexico.”

according to Night skyBetelgeuse will be visible for seven seconds, but it may be longer or shorter depending on your location.

“Each observer will see an event lasting 5 to 15 seconds,” Dr. Massey said.

“The expected time along the entire occultation path across Earth is from 01:08 to 01:26 GMT on December 12.”

It will only be visible along a narrow path that passes through parts of Asia and southern Europe including Spain, Italy, Florida and eastern Mexico.

Betelgeuse is a red giant – a dying star in the final stages of stellar evolution (artistic illustration)

Betelgeuse – usually the tenth brightest star in the night sky – is 950 times the size of the Sun and 642.5 light-years from Earth.

It is a red giant – a dying star in the final stages of stellar evolution – in the famous constellation Orion, named after the legendary hunter in Greek mythology.

Betelgeuse is easy to spot, and not only because of its brightness and red color.

It forms the “right shoulder” of the constellation Orion (or left shoulder, as seen from Earth) and can be seen just above the left of the famous belt – the line of three stars.

Right now, the much smaller asteroid 319 Leona is approaching Betelgeuse, which is only 45 miles (70 km) in diameter.

Because the asteroid is small, in order to see Betelgeuse covered, you need to be in a place where the star and asteroid are in almost perfect alignment with your location.

That's why its hidden path is so narrow, and why the whole world can't see it, according to Dr. Massey.

For those who can't see the event with their own eyes, you don't have to miss the event completely.

Betelgeuse experienced a dramatic dip in brightness in 2019, but that had nothing to do with any asteroid passing in front of it, scientists reported last year.

That's because the Virtual Telescope Project – which uses powerful robotic telescopes to broadcast cosmic events – is streaming them live over the Internet.

Live broadcast, Available on YouTubewill begin at 01:00 GMT and occultation should be completed within half an hour.

Gianluca Masi, director of the Virtual Telescope Project, said this rare event could help experts study the star and asteroid.

“This type of masking is very useful for constraining the shape of the asteroid in question,” Massey said in a statement.

“Here, we hope to even check the surface of the star in question as well – Betelgeuse.”

“It is a very large red giant, and as Leona will move in front of it as seen from Earth, we hope to be able to learn more about the large convection cells, which drive its changing brightness.”

Betelgeuse saw a huge dip in brightness in 2019, but this had nothing to do with any asteroid passing in front of it.

Scientists said last year that this was caused by a combination of sudden cooling and condensation of dust near the star.