Jul 22, 2020 04:30 AM
(This post was last modified: Jul 22, 2020 03:52 PM by C C.)
Did Betelgeuse eat another star?
https://www.syfy.com/syfywire/did-betelg...other-star
EXCERPT: A new study just published shows that, within the past few hundred thousand years, it’s entirely possible that Betelgeuse ate and digested a whole other star. This would explain at least one weird thing about it, and we know such stellar mergers can happen, so why not? It’s the least strange thing I’ve heard about Betelgeuse in the past couple of years anyway.
Betelgeuse is a red supergiant [...] Stars like this live for only some millions of years ... so it doesn’t have much time left. ... Stars like this should rotate extremely slowly. ... But here’s the weird thing: Betelgeuse spins rapidly. At its equator it rotates at a speed ... over four times faster than the Sun does.
[...] The new study looked into a possible answer: a binary merger, where Betelgeuse used to be two stars orbiting each other closely, but merged to form a single star. This happens a lot. First of all, binary stars are pretty common; half of all stars are in a binary system. If the more massive star (called the primary star) is more than about 15 times the Sun's mass it’ll evolve quickly ... If another star orbits it, the primary could swell up so much it engulfs the smaller, secondary star — that star will literally be inside the primary. ... The orbital energy of the secondary gets transferred to the primary’s atmosphere ... and the primary will start to rotate faster.
[...] As the secondary drops down the gravity of the primary’s dense core will start to tear the secondary star apart through tidal forces. ... This is what the new study found! They ran some simulations ... They found that in many cases they can reproduce Betelgeuse’s rapid rotation, and that it will continue to rotate rapidly like this for hundreds of thousands of years. Given that Betelgeuse will probably go supernova in 100,000 years, that timescale sounds about right... (MORE - details)
The SPHERE instrument on ESO’s Very Large Telescope has captured the first ever image of a young, Sun-like star accompanied by two giant exoplanets
First Image of a Multi-Planet System Around a Sun-like Star
https://www.youtube-nocookie.com/embed/JcoYA3HmuN8
https://www.syfy.com/syfywire/did-betelg...other-star
EXCERPT: A new study just published shows that, within the past few hundred thousand years, it’s entirely possible that Betelgeuse ate and digested a whole other star. This would explain at least one weird thing about it, and we know such stellar mergers can happen, so why not? It’s the least strange thing I’ve heard about Betelgeuse in the past couple of years anyway.
Betelgeuse is a red supergiant [...] Stars like this live for only some millions of years ... so it doesn’t have much time left. ... Stars like this should rotate extremely slowly. ... But here’s the weird thing: Betelgeuse spins rapidly. At its equator it rotates at a speed ... over four times faster than the Sun does.
[...] The new study looked into a possible answer: a binary merger, where Betelgeuse used to be two stars orbiting each other closely, but merged to form a single star. This happens a lot. First of all, binary stars are pretty common; half of all stars are in a binary system. If the more massive star (called the primary star) is more than about 15 times the Sun's mass it’ll evolve quickly ... If another star orbits it, the primary could swell up so much it engulfs the smaller, secondary star — that star will literally be inside the primary. ... The orbital energy of the secondary gets transferred to the primary’s atmosphere ... and the primary will start to rotate faster.
[...] As the secondary drops down the gravity of the primary’s dense core will start to tear the secondary star apart through tidal forces. ... This is what the new study found! They ran some simulations ... They found that in many cases they can reproduce Betelgeuse’s rapid rotation, and that it will continue to rotate rapidly like this for hundreds of thousands of years. Given that Betelgeuse will probably go supernova in 100,000 years, that timescale sounds about right... (MORE - details)
The SPHERE instrument on ESO’s Very Large Telescope has captured the first ever image of a young, Sun-like star accompanied by two giant exoplanets
First Image of a Multi-Planet System Around a Sun-like Star