# Betelgeuse becoming a black hole. **URL:** \ **Category:** Factual Questions\ **Created:** [January 23, 2011, 10:31pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704 "2011-01-23T22:31:44Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [January 23, 2011, 10:31pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/1 "2011-01-23T22:31:44Z")
Betelgeuse is due to go supernova any time now (any time in the next million years) and when it does I understand it _could_ create a black hole. So my question is, assuming it does, how long would it take from the initial explosion for a singularity to form? Years? Centuries? Millennia? Weeks? Also, at a distance of 1300 light years, could the resulting black hole have any influence on our own solar system or conditions here on Earth? Thanks in advance. ---
**Author:** ![Naxos](https://avatars.discourse-cdn.com/v4/letter/n/50afbb/32.png) [@Naxos](https://boards.straightdope.com/u/Naxos)\ **Post date:** [January 23, 2011, 10:39pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/2 "2011-01-23T22:39:45Z")
Probably minutes, if not even less. I’m not sure if it’s Betelgeuse’s axis of rotation that is pointing towards us, another star close to a super nova state that I was reading about is, but if that’s the case, its gamma ray emissions will definitely annihilate the solar system. ---
**Author:** ![appleciders](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@appleciders](https://boards.straightdope.com/u/appleciders)\ **Post date:** [January 23, 2011, 10:49pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/3 "2011-01-23T22:49:01Z")
Minutes or less. The black hole will be formed because of the violent supernova explosion, which happens extremely quickly. A black hole as small as the one that Betelgeuse would form would have no effect on us here on Earth. Its gravitational pull will be somewhat weaker with respect to us than Betelgeuse’s is now; that is, so small as to be impossible to measure. The supernova of formation might or might not affect us here. ---
**Author:** ![AlsoNamedBort](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alsonamedbort/32/3213_2.png) [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)\ **Post date:** [January 23, 2011, 10:49pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/4 "2011-01-23T22:49:24Z")
> [@Fiendish\_Astronaut](#): > > Also, at a distance of 1300 light years, could the resulting black hole have any influence on our own solar system or conditions here on Earth? When a star turns into a black hole, it’s gravity overall doesn’t increase. If our sun were to turn into a black hole today (ignoring all that supernova business) the Earth would continue to orbit it the same way. So it won’t affect us. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 23, 2011, 10:51pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/5 "2011-01-23T22:51:54Z")
Betelgeuse’s axis isn’t pointed _right_ at us, since we can see variations in the total brightness associated with the star’s rotation. I don’t remember off the top of my head what its inclination is, though. > [@](#): > > Also, at a distance of 1300 light years, could the resulting black hole have any influence on our own solar system or conditions here on Earth? The only influence would be that Orion would look funny without his shoulder. The gravity of a black hole is no different than the gravity of any other object with the same mass and at the same distance. Even if the Sun were to somehow turn into a black hole, it wouldn’t make any difference gravitationally (though of course we’d miss the sunlight). The only difference between a black hole and a “normal” object, gravitationally, is that you can get much closer to a black hole than to any other object of the same mass. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [January 23, 2011, 11:08pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/6 "2011-01-23T23:08:20Z")
> [@Naxos](#): > > another star close to a super nova state that I was reading about is > **[Real Death Star Could Strike Earth](https://www.space.com/5081-real-death-star-strike-earth.html)** > > A beautiful pinwheel in space might one day blast Earth with death rays. WR-104. 8,000 light years away. Not “fry the Earth like a potato in a microwave” distance, but still potential for big problems. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [January 24, 2011, 12:44am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/7 "2011-01-24T00:44:56Z")
I thought, as per an earlier thread of mine (board search hamster AWOL again), that it would take an infinite amount of time, from our perspective, for the singularity to actually form. As in, the event horizon will form, but then the collapse will seem to have frozen in time at that instant. ---
**Author:** ![Yumblie](https://avatars.discourse-cdn.com/v4/letter/y/76d3ee/32.png) [@Yumblie](https://boards.straightdope.com/u/Yumblie)\ **Post date:** [January 24, 2011, 1:03am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/8 "2011-01-24T01:03:37Z")
From an outsider’s perspective, it takes an infinite amount of time for anything, including the surface of a collapsing star, to cross an event horizon, due to gravitational time dilation. So from far away it would indeed take literally forever for Betelgeuse to collapse into a black hole. It would still look black though, because the stellar material would become infinitely redshifted as it fell in, so it effectively disappears anyway. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [January 24, 2011, 1:15am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/9 "2011-01-24T01:15:40Z")
> [@Naxos](#): > > …its gamma ray emissions will definitely annihilate the solar system. Surely that would just make the solar system larger and greener. ---
**Author:** ![SmithCommaJohn](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@SmithCommaJohn](https://boards.straightdope.com/u/SmithCommaJohn)\ **Post date:** [January 24, 2011, 1:22am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/10 "2011-01-24T01:22:08Z")
You wouldn’t like the solar system when it’s angry. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [January 24, 2011, 2:10am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/11 "2011-01-24T02:10:53Z")
Is “any time” literally true for Betelgeuse? I thought that the late evolution of massive stars involved changes that took place over short time periods- years, months or even days before the final collapse. Or are all these core events that would be unobservable from the outside? ---
**Author:** ![Peremensoe](https://avatars.discourse-cdn.com/v4/letter/p/ce7236/32.png) [@Peremensoe](https://boards.straightdope.com/u/Peremensoe)\ **Post date:** [January 24, 2011, 2:21am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/12 "2011-01-24T02:21:29Z")
FTR, most recent estimates put Betelgeuse at something like 640 LY from Sol. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 24, 2011, 3:14am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/13 "2011-01-24T03:14:32Z")
> [@](#): > > Is “any time” literally true for Betelgeuse? I thought that the late evolution of massive stars involved changes that took place over short time periods- years, months or even days before the final collapse. Or are all these core events that would be unobservable from the outside? There probably would be advance warnings, but having never before observed a star as it’s going through the last stages before supernova, who’s to say we would recognize any of them? Our theoretical models aren’t actually all _that_ great. That said, the estimates I’ve seen put the supernova as some time in the next thousand years, not the next million. Which means that there’s a plausible chance that it might have already gone off, and we’re just waiting to see it. So far as I know, it’s the only individual naked-eye-visible star for which that’s plausibly true. ---
**Author:** ![fuzzypickles](https://avatars.discourse-cdn.com/v4/letter/f/9d8465/32.png) [@fuzzypickles](https://boards.straightdope.com/u/fuzzypickles)\ **Post date:** [January 24, 2011, 5:55am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/14 "2011-01-24T05:55:08Z")
> [@Fiendish\_Astronaut](#): > > Betelgeuse is due to go supernova any time now (any time in the next million years) and when it does I understand it _could_ create a black hole. So my question is, assuming it does, how long would it take from the initial explosion for a singularity to form? Whatever you do, don’t say its name three times. ---
**Author:** ![ramel](https://avatars.discourse-cdn.com/v4/letter/r/eb8c5e/32.png) [@ramel](https://boards.straightdope.com/u/ramel)\ **Post date:** [January 24, 2011, 6:23am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/15 "2011-01-24T06:23:06Z")
People often misunderstand how black holes work. A star that has a certain amount of gravity, will have no more gravitation effect on objects if the star turns into a black hole. Think of it like this. The closer you get to something, the more strongly you feel its attraction. If you stood on the surface of a star, you are really close to the matter under your feet, but still pretty far from the rest of the star. Because the star is spread out there is a peak gravity you can experience. Any part of the star you get close to, means you’re getting further away from other parts of the star. But if you compress the star down to a point, like in a black hole, you can have the entire star just under your feet. You can be extremely close to every atom in the star, so you can feel its gravity much more strongly. That difference only matters if you’re pretty close. Once you’re getting millions of miles away in a typical planetary orbit, whether the star is spread out or compressed down to a point, the gravity you feel is pretty much the same because the distance to the matter is pretty much the same. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [January 24, 2011, 6:45am UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/16 "2011-01-24T06:45:32Z")
> [@Chronos](#): > > . > > That said, the estimates I’ve seen put the supernova as some time in the next thousand years, not the next million. . Then, would the gamma rays emissions affect us at this distance (640 LY according to another poster), or is this to far away? ---
**Author:** ![Ionizer](https://avatars.discourse-cdn.com/v4/letter/i/5daacb/32.png) [@Ionizer](https://boards.straightdope.com/u/Ionizer)\ **Post date:** [January 24, 2011, 1:04pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/17 "2011-01-24T13:04:18Z")
> [@clairobscur](#): > > Then, would the gamma rays emissions affect us at this distance (640 LY according to another poster), or is this to far away? There is no threat to Earth when Betelgeuse goes boom. [Here’s](http://blogs.discovermagazine.com/badastronomy/2010/06/01/is-betelgeuse-about-to-blow/) a great read from ‘Bad Astronomer’ Phil Plait. Earth is expected get a flood of neutrinos, but those so rarely interact with matter that its a total non-concern for us Earthlings’ safety. ---
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [January 24, 2011, 3:55pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/18 "2011-01-24T15:55:33Z")
Thanks everyone. What an event this would be, incredible. > [@Chronos](#): > > The only influence would be that Orion would look funny without his shoulder. No, Orion would have powered up and would have a SUPER SHOULDER. Ah no wait, it would be the same strength but just a lot smaller and less visible… Ah well. **Betelgeuse Betelgeuse Betelgeuse** ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [January 24, 2011, 4:25pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/19 "2011-01-24T16:25:10Z")
> [@Chimera](#): > > [Real Death Star Could Strike Earth | Space](http://www.space.com/5081-real-death-star-strike-earth.html) > > WR-104. 8,000 light years away. Not “fry the Earth like a potato in a microwave” distance, but still potential for big problems. From the article: > [@](#): > > Both the massive stars in WR 104 will one day explode as supernovae. However, one of the pair is a highly unstable star known as a Wolf-Rayet, the last known stable phase in the life of these massive stars right before a supernova. Anyone care to speculate what the effect Wolf-Raye going nova will have on the other star? ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [January 24, 2011, 4:33pm UTC](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704/20 "2011-01-24T16:33:11Z")
But if Betelgeuse is (wioll haven be) a black hole, won’t that be mentioned (mayan’t mentionan on-when) when Ford, Zaphod, Arthur, and Trillian are at the Restaurant at the End of the Universe? [Next page](https://boards.straightdope.com/t/betelgeuse-becoming-a-black-hole/568704.md?page=2)