New Zealand Local Weather Forum
Climate and Science => Space, Science and Nature => Topic started by: Mark on February 12, 2020, 08:55:15 PM
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Feb 21st is the day we’ll know if the puzzling dimming of Betelgeuse is just an alignment of dimming cycles in a highly variable star, or a prelude to a supernova we’ll be able to witness with our bare eyes. If it happens, the dying star will be visible in the daytime and shine as bright as the moon.
From Spaceweather.com :
heres the link https://www.spaceweather.com/archive.php?view=1&day=09&month=02&year=2020
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https://www.spaceweather.com/
BETELGEUSE IS BRIGHTENING AGAIN: "Don't panic! Betelgeuse is not likely to undergo a supernova explosion anytime soon," says South Korean research astronomer Bum-Suk Yeom. "The red supergiant star Betelgeuse appears to have finally stopped its unprecedented dimming. It's been brightening over the last few days." Yoem assembled this light curve from data collected by American Association of Variable Star Observers (AAVSO):
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https://www.spaceweather.com/
A NEW FORM OF SPACE WEATHER ON BETELGEUSE: You've heard of a CME, a "coronal mass ejection." They happen all the time. A piece of the sun's tenuous outer atmosphere (corona) blows off and sometimes hits Earth. Something far more terrible has happened to Betegeuse. The red giant star produced an SME, or "surface mass ejection."
Above: An artist's concept of an SME on Betelgeuse. Credit: Elizabeth Wheatley (STScI)
NASA astronomers believe that in 2019 a colossal piece of Betelgeuse's surface blew off the star. The mass of the SME was 400 billion times greater than a CME or several times the mass of Earth's Moon. Data from multiple telescopes, especially Hubble, suggest that a convective plume more than a million miles across bubbled up from deep inside the star, producing shocks and pulsations that blasted a chunk off the surface.
"We've never before seen such a huge mass ejection from the surface of a star," says Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics, who is leading the study. "Something is going on that we don't completely understand."
After it left the star, the SME cooled, forming a dark cloud that famously dimmed Betelgeuse in 2019 and 2020. Even casual sky watchers could look up and see the change. Some astronomers worried that the dimming foreshadowed a supernova explosion. The realization that an SME is responsible has at least temporarily calmed those fears.
Above: A Hubble image of Betelgeuse located in the shoulder of Orion.
Betelgeuse's brightness has since returned to normal, but something strange is still going on. Astronomers have long known that Betelgeuse is a variable star with a 430-day period. Its metronome-like change in brightness has been observed for more than 200 years. As Betelgeuse recovers, however, those pulsations are no longer regular: See the data. Spectra taken by Hubble and the Tillinghast telescope in Arizona imply that years later the surface of Betelgeuse is still bouncing like a plate of gelatin dessert--a testament to the ferocity of the blowout.
Betelgeuse is so large that if it replaced the sun at the center of our solar system, its atmosphere would extend past Jupiter. Dupree used Hubble to resolve hot spots on the star's surface in 1996. This was the first direct image of a star other than the sun.
What's happening now "is a totally new phenomenon that we can observe directly and resolve surface details with Hubble," says Dupree. "We're watching stellar evolution in real time."
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A cosmic drama may soon unfold as Betelgeuse, the red supergiant in Orion, approaches its final days. Astronomers warn that when this colossal star goes supernova, its explosion could be so brilliant it might even be seen in daylight.
Betelgeuse has long intrigued scientists with its immense size and unpredictable changes. Recent data shows it’s losing mass at a faster rate, signaling a potential imminent explosion. When the supernova occurs, the star will release an extraordinary amount of energy, outshining the night sky and possibly casting an unusual glow across the planet.
This event could be one of the brightest supernovae observed in human history. Astronomers worldwide are ready to record every moment, while enthusiasts await a rare spectacle that may never happen again in our lifetime. Beyond its visual impact, the supernova will shed light on the evolution of massive stars and the cosmic processes that create the building blocks of life.
Betelgeuse is preparing for its spectacular farewell — a cosmic performance that promises wonder, insight, and a sky transformed like never before.
#DeepUniverse