A year ago, the bright red star Betelgeuse Gemini In the constellation Orion made headlines when star-watchers noticed a stark faint ring that astronomers couldn’t explain. They are still unable, even though they keep trying.
The suspense is especially high now, because the star, who usually dims and lights up on a regular schedule, should soon start fading again, for the first time since the bizarre antics of last year. Scientists hope this year’s Betelgeuse observations will put last year’s episode in context, which may shape astronomers’ understanding of stellar activities in general. An astronomer shared an update at the 237th meeting for American Astronomical Society, Which was held roughly in January, ahead of the blackout expected to occur in April of this year.
“We want to see if last year was really unique,” Andrea Dupre, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, told Space.com after the conference.
“What if it happened again? Then I don’t know,” she said. “I don’t know if it will be a once in a lifetime [event] Or whether it will happen again or is it now in a new phase and what this means? “
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What she and her colleagues know is that scientists have been recording detailed observations of Betelgeuse for 150 years, and nowhere in these records is anything like a vanishing event last year. Usually, the star dims and lights up during a cycle of about 420 days in a rhythm similar to breathing, growing and shrinking in size and luminosity alike.
But in December 2019, sky-watchers noticed that something strange was happening when Orbiter began to darken.
“The situation was not as dull as it was in February,” Dupre said. Even just staring at the stars, she said, viewing Betelgeuse from Honolulu in early January during the 235th meeting of the American Astronomical Society, the difference was palpable. “The constellation looked strange, utterly strange. The bright red star at the shoulder Orion He was not there, he was weaker than the others. This is not what you are supposed to be. “
Some observers had hoped this was a sign that humans were about to take a front seat in the tragic demise of Orchid. As an ancient red giant, According to NASA, Betelgeuse is doomed to a chaotic fate: when the star runs out of fuel, it will explode in a bright supernova, hurling its guts across the cosmic neighborhood. (In fact, the star may already have done it, and scientists are just waiting to see what comes next.)
Dupre didn’t think that was the most likely scenario for last year’s strange events. But if scientists did indeed discover the Betelgeuse in time, right before it detonated, the observations would be unprecedented.
“Nobody knows what a star is doing before he goes SupernovaDupre said. People looked maybe six months or two years ago, but until we perform a nighttime survey of the entire sky and all of the sky, we have no information about what is happening the night before it erupted. “
Even if a supernova doesn’t materialize soon, more notes of the bright Betelgeuse are still useful, especially when the star is doing anything out of the ordinary. “The sun is really the only star that we can see in detail and see what happens,” Dupre said. “Orbit is the second best candidate.”
In particular, she hopes Betelgeuse will be able to teach astronomers about stellar explosions. Using Hubble Space Telescope observations collected in the fall of 2019, just before Betelgeuse began to dim, scientists concluded that the star is spitting out a huge amount of dense gas, Dupre said. This in and of itself is not surprising, Dupre said, although it is strange that this explosion came from a different region of the star from what scientists previously observed.
Be suspected That as this mass continues to move away from Orbit of Gemini, it has slowly cooled into dust – dust that you think could have caused the apparent fading that was so striking last year.Other astronomers believe the ejection was a coincidence, and that a large cold spot on the star’s surface Caused a strange fade.
Dupre hopes that observing the Orbit of Gemini this year will help scientists distinguish between these two scenarios and address additional questions such as the strange location of the explosion.
“How does a star lose its substance?” She said. “Does it flow gently? Does it come out in bursts? Does it come from different parts of the star? How does it change when it moves from the surface of the star, which is hot, to the cold interstellar medium?”
Fittingly, last year’s blackout happened roughly halfway through a three-year program that Dupre had already arranged. Hubble Space Telescope To check-in on Betelgeuse four times a year. It is some of these Hubble observations that have observed the mass of matter emerging from the star before it begins to darken.
Most recently, Hubble checked out the star in February. Dupre said the last dedicated observations will happen in April, though she plans to request extra time with Hubble due to the star’s recent activity.
But Betelgeuse is a difficult target. From late April to late August, it was too close to the Sun in our sky to be seen by Hubble and Earth’s devices, Dupre said. This is particularly inconvenient given that the star’s usual cycle of about 240 days would make it look just as bright as humans cannot see it.
In between Hubble’s observations last summer, Dupre enlisted the NASA Solar Spacecraft Stereo-prof, Is located in about a third of the orbit behind Earth. When the Sun blocks Planet Gemini from Earth, the spacecraft has a clear view of the star. The spacecraft will make four or five more observations this summer, after Hubble’s last chance to see the star this spring.
For now, the star continues to keep astronomers wary.
“The Orbit of Gemini is“ quiet, ”Dupre wrote in an email update on March 1, adding that she began to suspect that the star would not make it fade expected in April, according to the schedule he had been following for many years.“ That explosion may have changed in 2019. His personality!
Whether or not the Betelgeuse fades, Dupre and her co-workers will watch, eager to refine the star’s secrets. She said, “We’ll see, that’s always the fun thing!”
Email Megan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us On Twitter @Spacedotcom, and on Facebook.
