Discover and read the best of Twitter Threads about #Betelgeuse
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Message from the organizers:
It’s been an incredible experience hosting the Sandstorm hackathon. Thank you to all of the participants and sponsors who helped make this possible!
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It’s been an incredible experience hosting the Sandstorm hackathon. Thank you to all of the participants and sponsors who helped make this possible!
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We hope that Sandstorm helped push the ecosystem forward when Solana needed it most, and we look forward to seeing you continue to develop your projects!
- @LamportDAO core contributors @solblaze_org, @0xMert_, @ThalesHXRO, and @0xSoju
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- @LamportDAO core contributors @solblaze_org, @0xMert_, @ThalesHXRO, and @0xSoju
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So! Last week @MassiveStarGuy and I got some nice data and found out that #Betelgeuse's recent dimming was NOT caused by a drop in the star's surface temperature.
A thread!
arxiv.org/abs/2002.10463
A thread!
arxiv.org/abs/2002.10463
@MassiveStarGuy Starting in October, Betelgeuse started dimming pretty impressively, and astronomers started tossing around ideas for what might be causing this sudden drop in the star's visual brightness. I wrote a thread summarizing the possibilities back in December:
@MassiveStarGuy One popular idea was that Betelgeuse looked dimmer because its surface was cooler. Like all red supergiants, Betelgeuse has enormous convective cells that dominate its surface appearance, boiling away and creating what look like big hot and cool spots:
Here are some news about #Betelgeuse! Robin Leadbeater, an amateur spectroscopist, has just posted the evolution of Betelgeuse's spectrum in the near-infrared. On this graph, we can see the spectra from the 4th of February and from the 28th of December, as well as the ratio
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between the two (in pink). As we can see, for the past 2 months, the near-IR brightness of Betelgeuse remained mainly unchanged (ratio between 1 and 1.02) EXCEPT for the H-alpha absorption band.
Its luminosity was multiplied by 1.2 for the last two months! That is
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Its luminosity was multiplied by 1.2 for the last two months! That is
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significantly higher than the rest of the far-IR spectrum.
But was is the H-alpha absorption band? It's the spectral line of a wavelength of 656 nm, indicating that a hydrogen electron jumped from an energy level to a higher energy level (2 -> 3).
Why does it jump? Because
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But was is the H-alpha absorption band? It's the spectral line of a wavelength of 656 nm, indicating that a hydrogen electron jumped from an energy level to a higher energy level (2 -> 3).
Why does it jump? Because
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As you might have seen it, @LIGO has detected some weird gravitational waves. I took more than a day to take the time to read everything about it. So, is this new candidate related to #Betelgeuse?
Let's go for a little thread!
Let's go for a little thread!
Contrarily to what some people said, Betelgeuse is NOT in the 90% zone for the GW. As you can see, it is next to it, probably in the 95% zone. So we cannot exclude that it comes from Betelgeuse, but it is unlikely.
Also, no unusual gamma-rays...
1/10 All eyes on #Betelgeuse these days. What’s happening to this well-known star in the constellation of #Orion?
2/10 Normally one of the brightest stars in the sky, it’s now fainter than ever before in recorded history.
3/10 Astronomers think the star is preparing to blow, going #supernova. Think cosmic time scales though. This artist’s impression shows #Betelgeuse shedding its material. eso.org/public/images/…
Credit: @ESO /L. Calçada
Credit: @ESO /L. Calçada
Why do we know #Betelgeuse may go #Supernova within the next few 100000 years, but most likely not soon? And why are we sure the Sun will be a safe star for Billions of years?
A brief primer #thread to Stellar Evolution. 1/
Sun: SDO. Betelgeuse: ESO/ALMA
#astronomy #Space
A brief primer #thread to Stellar Evolution. 1/
Sun: SDO. Betelgeuse: ESO/ALMA
#astronomy #Space
First thing to know is: stars are not all alike. They are big, small, bright, dim, have different colors and die different deaths. The quantity at the root of their diversity is their MASS. Stars have masses between roughly 0.1 & 100 times the Sun’s mass. Large ones are rare.2/
Here is the fundamental diagram of stellar evolution. It’s called the Hertzsprung-Russell Diagram (HRD). The further left you go, the hotter stars become. The further up you go, the brighter stars become. 3/
(Pic: ESO)
(Pic: ESO)
Je me sens coupable d'avoir fait un thread en 🇬🇧 et pas en 🇫🇷. On va rattraper ça. En 2014, j'ai soutenu ma thèse avec pour objet principal #Betelgeuse. Cette étoile subit une baisse de luminosité inhabituelle. Récap de ce qu'on sait sur elle 👇 (Image apod.nasa.gov/apod/ap101117.…)
Tout d'abord, Bételgeuse est l'étoile rouge en haut à gauche de la constellation d'Orion. C'est une supergéante rouge, une étoile massive (15 fois la masse du Soleil) qui explosera un jour en supernova à la fin de sa vie.
D'après L. Z. Fang (1981), au 1er siècle av JC, des astronomes chinois ont identifié #Betelgeuse comme jaune (alors qu'ils notent bien qu'Antares était rouge). Une erreur ? Signe d'un changement de couleur de l'étoile depuis ? Serait-elle alors une jeune supergéante rouge ?
#Betelgeuse is so huge that astronomers can map its surface! This sequence shows 5 years of bright & dark churning on the red giant star (+ more great info in the thread below).
For context, Betelgeuse is about 1,000 times as wide as the Sun, and 100,000 times as wide as the Earth. eso.org/public/images/…
@ESO The derived maps of #Betelgeuse look a lot like computer simulations of the surface of a red giant star by Bern Freytag. For now, this is the closest we can get to seeing a red giant up close. astro.uu.se/~bf/movie/dst3…
I cannot remain silent about #Betelgeuse. After all, it was the main subject of my PhD. I offer you below a recap of my favorite results on this star. (Image: apod.nasa.gov/apod/ap101117.…)
First, according to L. Z. Fang (1981) in the 1st century BC, Chinese astronomers identified Betelgeuse as yellow (while Antares was identified as red). Mistake ? Indicative of a young red supergiant ?
More recently, of course, I cannot not cite Michelson & Pease 1921 who first determined the angular diameter of a star other than the Sun. Which star ? Betelgeuse of course ! It was @MtWilsonObs and you can still see their instrument and the domes of the CHARA array there.
Today, I saw that a lot of astronomers/astrophysicists were talking about #Betelgeuse . Indeed, according to many, Betelgeuse luminosity seems to be quite low. Some say it’s extraordinary, others say it happens quite often, but all (secretly or not) hope for a supernova. 1/7
Even if I don’t believe it is likely that a supernova will happen in the next weeks, I wanted to know if this dimming was actually extraordinary. I looked at the AAVSO data, like everyone. At first, I saw what I already saw on Twitter (see figure): it seemed like it already 2/7
happened 5 times during the last 50 years. But I dug a little deeper, and I saw that in November 1985, when the luminosity was very low, a group of astronomers (Rodrigues A., Paulo) had made many measurements. ALL were very low in brightness (most around 1.8), and quite far 3/7
