What would happen if someone had a telescope and watched Betelgeuse when it goes supernova?
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Would that person go blind?
Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain telescopes that could handle the brightness towards it.
I'm curious if an individual with a telescope pointed in that direction would have an unpleasant surprise. Would the scientific community be wise to not announce the massive stellar explosion until after it's visible to avoid potential negative effects from over-eager amateur astronomers.
I realize this is a kind of silly question and it might depend too much on the telescope, but I'm curious.
telescope amateur-observing supernova
add a comment |
up vote
19
down vote
favorite
Would that person go blind?
Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain telescopes that could handle the brightness towards it.
I'm curious if an individual with a telescope pointed in that direction would have an unpleasant surprise. Would the scientific community be wise to not announce the massive stellar explosion until after it's visible to avoid potential negative effects from over-eager amateur astronomers.
I realize this is a kind of silly question and it might depend too much on the telescope, but I'm curious.
telescope amateur-observing supernova
4
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
10
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday
add a comment |
up vote
19
down vote
favorite
up vote
19
down vote
favorite
Would that person go blind?
Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain telescopes that could handle the brightness towards it.
I'm curious if an individual with a telescope pointed in that direction would have an unpleasant surprise. Would the scientific community be wise to not announce the massive stellar explosion until after it's visible to avoid potential negative effects from over-eager amateur astronomers.
I realize this is a kind of silly question and it might depend too much on the telescope, but I'm curious.
telescope amateur-observing supernova
Would that person go blind?
Neutrino detectors and the abundance of Neutrinos would detect the upcoming visible show about 3 hours before any visible signs, so there would be time to point certain telescopes that could handle the brightness towards it.
I'm curious if an individual with a telescope pointed in that direction would have an unpleasant surprise. Would the scientific community be wise to not announce the massive stellar explosion until after it's visible to avoid potential negative effects from over-eager amateur astronomers.
I realize this is a kind of silly question and it might depend too much on the telescope, but I'm curious.
telescope amateur-observing supernova
telescope amateur-observing supernova
asked 2 days ago
userLTK
15.6k12043
15.6k12043
4
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
10
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday
add a comment |
4
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
10
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday
4
4
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
10
10
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday
add a comment |
4 Answers
4
active
oldest
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up vote
30
down vote
accepted
No, it would not be a problem. Supernovae are not at all like flashbulbs – they brighten over a period of many days and dim again even more slowly. Here are a number of different light curves taken from Wikipedia:
The rise is fast on an astronomical scale – several orders of magnitude over a period of roughly ten days – but very slow on a human scale. An amateur looking at it would not notice any significant change in brightness, but if the same person came back a few hours later or the next night, the change would be very evident.
As far as we can tell, the reason is that the light at peak brightness is caused by emissions from material blown off by the explosion. For example, in Type 1a SNe, most of the light is from the radioactive decay of the huge mass of ejected nickel-56 (half life 6 days).
The Wikipedia article on supernovae is quite good and covers this all in more detail.
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
add a comment |
up vote
16
down vote
If you insist on observing the exploding Betelgeuse at peak brightness, you could potentially damage your eye. The complete answer enters the realm of physiology. Here I'll discuss the astronomical parts:
Betelgeuse will explode as a type II supernova, the typical brightness of which is around $M sim -17$. With a distance of $dsimeq200,mathrm{pc}$, its distance modulus is
$$
mu = 5log(d/mathrm{pc}) - 5 simeq 6.5,
$$
so its apparent magnitude will be
$$
m = M + mu simeq -10.5.
$$
For these calculation I assume that the Sun is the threshold for damaging your eye (a brief look at the Sun is okay, a longer look will cause permanent damage. But… physiology…).
The Sun has an apparent magnitude of $m_odot = -26.7$, i.e. it is $Delta m = 16.2$ magnitudes brighter. In other words, Betelgeuse will be
$$
f = 10^{Delta m/2.5} simeq 3times10^6
$$
times dimmer than the Sun.
However, the Sun is an extended source, spanning an angle of roughly $theta_mathrm{Sun} = 32$ arcminutes across. In contrast, Betelgeuse is a point source, which when transferred through the atmosphere and the telescope, is spread out over $theta_mathrm{Betelgeuse} sim$ a few square arcseconds. Thus its light will be more concentrated; i.e. it will be much brighter, but it will hit a much smaller area of your retina. However, your eye will also move around, smearing out the light. Not being a physiologist, for the sake of this calculation I assume that the light is smeared out over a region of a radius of 1 arcminute (about the size of a planet seen from Earth).
Hence, the factor $f$ will itself be a factor $(theta_mathrm{Betelgeuse} / theta_mathrm{Sun})^2 simeq 800$ times larger — that is, Betelgeuse is only $sim 3,700$ times dimmer than the Sun.
Hence, for our assumptions your eye will be damaged if you observe exploding Betelgeuse through a telescope with an area $sim 3,700$ larger — or roughly 60 times wider — than your pupil. In bright light, the pupil contracts to roughly 3 mm in diameter, so if observing through a telescope of 18 cm or larger, you could damage your eye.
Based on evolutionary models of Betelgeuse, Dolan et al. (2016) estimate an apparent magnitude of $m=-12.4$, i.e. roughly 6 times brighter than our estimate. This would mean that you only need a 3 cm telescope to damage your eye.
However, as Mark writes in his answer, supernovae don't increase to their peak brightness in matters of seconds, but rather in matters days (roughly half a mag per day), so you have plenty of time to look away.
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
|
show 1 more comment
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3
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Brightness varies inversely with the square of the distance. Betelgeuse is about 642.5 light years away and has an apparent magnitude of 0.42. My grasp of apparent magnitude concepts is a bit wobbly, but I believe if it grew a million times as bright, it might have an apparent magnitude of -14.5 or so, which is a lot more like the brightness of the moon than the sun.
Given the great distance, the decrease in brightness due to distance, and the countless amounts of dust & gas between earth and Betelgeuse, I think you'd probably be fine. You might be dazzled by its brightness -- a bit like looking at a light bulb, I imagine -- but I doubt it would cause any physical harm.
EDIT: I hope a real astronomer sounds off here. I'm not sure what kind of supernova we might expect from Betelgeuse, but apparently supernovas (supernovae?) can achieve a theoretical brightness equal to 5 trillion suns!
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
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up vote
0
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Funnily enough I was watching a video about this yesterday.
Although it would be very bright it would not reach anywhere near the brightness of the sun. It would probably rival the moon.
Worth watching:
https://www.youtube.com/watch?v=hJPVuSNFxlY
New contributor
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
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4 Answers
4
active
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4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
30
down vote
accepted
No, it would not be a problem. Supernovae are not at all like flashbulbs – they brighten over a period of many days and dim again even more slowly. Here are a number of different light curves taken from Wikipedia:
The rise is fast on an astronomical scale – several orders of magnitude over a period of roughly ten days – but very slow on a human scale. An amateur looking at it would not notice any significant change in brightness, but if the same person came back a few hours later or the next night, the change would be very evident.
As far as we can tell, the reason is that the light at peak brightness is caused by emissions from material blown off by the explosion. For example, in Type 1a SNe, most of the light is from the radioactive decay of the huge mass of ejected nickel-56 (half life 6 days).
The Wikipedia article on supernovae is quite good and covers this all in more detail.
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
add a comment |
up vote
30
down vote
accepted
No, it would not be a problem. Supernovae are not at all like flashbulbs – they brighten over a period of many days and dim again even more slowly. Here are a number of different light curves taken from Wikipedia:
The rise is fast on an astronomical scale – several orders of magnitude over a period of roughly ten days – but very slow on a human scale. An amateur looking at it would not notice any significant change in brightness, but if the same person came back a few hours later or the next night, the change would be very evident.
As far as we can tell, the reason is that the light at peak brightness is caused by emissions from material blown off by the explosion. For example, in Type 1a SNe, most of the light is from the radioactive decay of the huge mass of ejected nickel-56 (half life 6 days).
The Wikipedia article on supernovae is quite good and covers this all in more detail.
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
add a comment |
up vote
30
down vote
accepted
up vote
30
down vote
accepted
No, it would not be a problem. Supernovae are not at all like flashbulbs – they brighten over a period of many days and dim again even more slowly. Here are a number of different light curves taken from Wikipedia:
The rise is fast on an astronomical scale – several orders of magnitude over a period of roughly ten days – but very slow on a human scale. An amateur looking at it would not notice any significant change in brightness, but if the same person came back a few hours later or the next night, the change would be very evident.
As far as we can tell, the reason is that the light at peak brightness is caused by emissions from material blown off by the explosion. For example, in Type 1a SNe, most of the light is from the radioactive decay of the huge mass of ejected nickel-56 (half life 6 days).
The Wikipedia article on supernovae is quite good and covers this all in more detail.
No, it would not be a problem. Supernovae are not at all like flashbulbs – they brighten over a period of many days and dim again even more slowly. Here are a number of different light curves taken from Wikipedia:
The rise is fast on an astronomical scale – several orders of magnitude over a period of roughly ten days – but very slow on a human scale. An amateur looking at it would not notice any significant change in brightness, but if the same person came back a few hours later or the next night, the change would be very evident.
As far as we can tell, the reason is that the light at peak brightness is caused by emissions from material blown off by the explosion. For example, in Type 1a SNe, most of the light is from the radioactive decay of the huge mass of ejected nickel-56 (half life 6 days).
The Wikipedia article on supernovae is quite good and covers this all in more detail.
edited yesterday
CJ Dennis
1946
1946
answered 2 days ago
Mark Olson
4,468818
4,468818
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
add a comment |
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
1
1
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
This answer explains that the brightness increases gradually, but doesn't seem to answer the question as to whether or not a person watching Betelgeuse would go blind (unless we count "no, it would not be a problem" as the answer).
– JBentley
18 hours ago
6
6
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
Note that the OP asked if there'd be an "unpleasant surprise" -- the answer is, "No, there would be no surprise." You would not be blinded unless you really wanted to be. Obviously if you stare into a bright enough light with a big enough telescope for a long enough time you can blind yourself in one eye -- you'd have to do it all over again with the other, of course. I don't feel that constitutes a "surprise."
– Mark Olson
17 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
@JBentley It's not fast enough and it's not bright enough to blind you.
– Florin Andrei
12 hours ago
add a comment |
up vote
16
down vote
If you insist on observing the exploding Betelgeuse at peak brightness, you could potentially damage your eye. The complete answer enters the realm of physiology. Here I'll discuss the astronomical parts:
Betelgeuse will explode as a type II supernova, the typical brightness of which is around $M sim -17$. With a distance of $dsimeq200,mathrm{pc}$, its distance modulus is
$$
mu = 5log(d/mathrm{pc}) - 5 simeq 6.5,
$$
so its apparent magnitude will be
$$
m = M + mu simeq -10.5.
$$
For these calculation I assume that the Sun is the threshold for damaging your eye (a brief look at the Sun is okay, a longer look will cause permanent damage. But… physiology…).
The Sun has an apparent magnitude of $m_odot = -26.7$, i.e. it is $Delta m = 16.2$ magnitudes brighter. In other words, Betelgeuse will be
$$
f = 10^{Delta m/2.5} simeq 3times10^6
$$
times dimmer than the Sun.
However, the Sun is an extended source, spanning an angle of roughly $theta_mathrm{Sun} = 32$ arcminutes across. In contrast, Betelgeuse is a point source, which when transferred through the atmosphere and the telescope, is spread out over $theta_mathrm{Betelgeuse} sim$ a few square arcseconds. Thus its light will be more concentrated; i.e. it will be much brighter, but it will hit a much smaller area of your retina. However, your eye will also move around, smearing out the light. Not being a physiologist, for the sake of this calculation I assume that the light is smeared out over a region of a radius of 1 arcminute (about the size of a planet seen from Earth).
Hence, the factor $f$ will itself be a factor $(theta_mathrm{Betelgeuse} / theta_mathrm{Sun})^2 simeq 800$ times larger — that is, Betelgeuse is only $sim 3,700$ times dimmer than the Sun.
Hence, for our assumptions your eye will be damaged if you observe exploding Betelgeuse through a telescope with an area $sim 3,700$ larger — or roughly 60 times wider — than your pupil. In bright light, the pupil contracts to roughly 3 mm in diameter, so if observing through a telescope of 18 cm or larger, you could damage your eye.
Based on evolutionary models of Betelgeuse, Dolan et al. (2016) estimate an apparent magnitude of $m=-12.4$, i.e. roughly 6 times brighter than our estimate. This would mean that you only need a 3 cm telescope to damage your eye.
However, as Mark writes in his answer, supernovae don't increase to their peak brightness in matters of seconds, but rather in matters days (roughly half a mag per day), so you have plenty of time to look away.
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
|
show 1 more comment
up vote
16
down vote
If you insist on observing the exploding Betelgeuse at peak brightness, you could potentially damage your eye. The complete answer enters the realm of physiology. Here I'll discuss the astronomical parts:
Betelgeuse will explode as a type II supernova, the typical brightness of which is around $M sim -17$. With a distance of $dsimeq200,mathrm{pc}$, its distance modulus is
$$
mu = 5log(d/mathrm{pc}) - 5 simeq 6.5,
$$
so its apparent magnitude will be
$$
m = M + mu simeq -10.5.
$$
For these calculation I assume that the Sun is the threshold for damaging your eye (a brief look at the Sun is okay, a longer look will cause permanent damage. But… physiology…).
The Sun has an apparent magnitude of $m_odot = -26.7$, i.e. it is $Delta m = 16.2$ magnitudes brighter. In other words, Betelgeuse will be
$$
f = 10^{Delta m/2.5} simeq 3times10^6
$$
times dimmer than the Sun.
However, the Sun is an extended source, spanning an angle of roughly $theta_mathrm{Sun} = 32$ arcminutes across. In contrast, Betelgeuse is a point source, which when transferred through the atmosphere and the telescope, is spread out over $theta_mathrm{Betelgeuse} sim$ a few square arcseconds. Thus its light will be more concentrated; i.e. it will be much brighter, but it will hit a much smaller area of your retina. However, your eye will also move around, smearing out the light. Not being a physiologist, for the sake of this calculation I assume that the light is smeared out over a region of a radius of 1 arcminute (about the size of a planet seen from Earth).
Hence, the factor $f$ will itself be a factor $(theta_mathrm{Betelgeuse} / theta_mathrm{Sun})^2 simeq 800$ times larger — that is, Betelgeuse is only $sim 3,700$ times dimmer than the Sun.
Hence, for our assumptions your eye will be damaged if you observe exploding Betelgeuse through a telescope with an area $sim 3,700$ larger — or roughly 60 times wider — than your pupil. In bright light, the pupil contracts to roughly 3 mm in diameter, so if observing through a telescope of 18 cm or larger, you could damage your eye.
Based on evolutionary models of Betelgeuse, Dolan et al. (2016) estimate an apparent magnitude of $m=-12.4$, i.e. roughly 6 times brighter than our estimate. This would mean that you only need a 3 cm telescope to damage your eye.
However, as Mark writes in his answer, supernovae don't increase to their peak brightness in matters of seconds, but rather in matters days (roughly half a mag per day), so you have plenty of time to look away.
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
|
show 1 more comment
up vote
16
down vote
up vote
16
down vote
If you insist on observing the exploding Betelgeuse at peak brightness, you could potentially damage your eye. The complete answer enters the realm of physiology. Here I'll discuss the astronomical parts:
Betelgeuse will explode as a type II supernova, the typical brightness of which is around $M sim -17$. With a distance of $dsimeq200,mathrm{pc}$, its distance modulus is
$$
mu = 5log(d/mathrm{pc}) - 5 simeq 6.5,
$$
so its apparent magnitude will be
$$
m = M + mu simeq -10.5.
$$
For these calculation I assume that the Sun is the threshold for damaging your eye (a brief look at the Sun is okay, a longer look will cause permanent damage. But… physiology…).
The Sun has an apparent magnitude of $m_odot = -26.7$, i.e. it is $Delta m = 16.2$ magnitudes brighter. In other words, Betelgeuse will be
$$
f = 10^{Delta m/2.5} simeq 3times10^6
$$
times dimmer than the Sun.
However, the Sun is an extended source, spanning an angle of roughly $theta_mathrm{Sun} = 32$ arcminutes across. In contrast, Betelgeuse is a point source, which when transferred through the atmosphere and the telescope, is spread out over $theta_mathrm{Betelgeuse} sim$ a few square arcseconds. Thus its light will be more concentrated; i.e. it will be much brighter, but it will hit a much smaller area of your retina. However, your eye will also move around, smearing out the light. Not being a physiologist, for the sake of this calculation I assume that the light is smeared out over a region of a radius of 1 arcminute (about the size of a planet seen from Earth).
Hence, the factor $f$ will itself be a factor $(theta_mathrm{Betelgeuse} / theta_mathrm{Sun})^2 simeq 800$ times larger — that is, Betelgeuse is only $sim 3,700$ times dimmer than the Sun.
Hence, for our assumptions your eye will be damaged if you observe exploding Betelgeuse through a telescope with an area $sim 3,700$ larger — or roughly 60 times wider — than your pupil. In bright light, the pupil contracts to roughly 3 mm in diameter, so if observing through a telescope of 18 cm or larger, you could damage your eye.
Based on evolutionary models of Betelgeuse, Dolan et al. (2016) estimate an apparent magnitude of $m=-12.4$, i.e. roughly 6 times brighter than our estimate. This would mean that you only need a 3 cm telescope to damage your eye.
However, as Mark writes in his answer, supernovae don't increase to their peak brightness in matters of seconds, but rather in matters days (roughly half a mag per day), so you have plenty of time to look away.
If you insist on observing the exploding Betelgeuse at peak brightness, you could potentially damage your eye. The complete answer enters the realm of physiology. Here I'll discuss the astronomical parts:
Betelgeuse will explode as a type II supernova, the typical brightness of which is around $M sim -17$. With a distance of $dsimeq200,mathrm{pc}$, its distance modulus is
$$
mu = 5log(d/mathrm{pc}) - 5 simeq 6.5,
$$
so its apparent magnitude will be
$$
m = M + mu simeq -10.5.
$$
For these calculation I assume that the Sun is the threshold for damaging your eye (a brief look at the Sun is okay, a longer look will cause permanent damage. But… physiology…).
The Sun has an apparent magnitude of $m_odot = -26.7$, i.e. it is $Delta m = 16.2$ magnitudes brighter. In other words, Betelgeuse will be
$$
f = 10^{Delta m/2.5} simeq 3times10^6
$$
times dimmer than the Sun.
However, the Sun is an extended source, spanning an angle of roughly $theta_mathrm{Sun} = 32$ arcminutes across. In contrast, Betelgeuse is a point source, which when transferred through the atmosphere and the telescope, is spread out over $theta_mathrm{Betelgeuse} sim$ a few square arcseconds. Thus its light will be more concentrated; i.e. it will be much brighter, but it will hit a much smaller area of your retina. However, your eye will also move around, smearing out the light. Not being a physiologist, for the sake of this calculation I assume that the light is smeared out over a region of a radius of 1 arcminute (about the size of a planet seen from Earth).
Hence, the factor $f$ will itself be a factor $(theta_mathrm{Betelgeuse} / theta_mathrm{Sun})^2 simeq 800$ times larger — that is, Betelgeuse is only $sim 3,700$ times dimmer than the Sun.
Hence, for our assumptions your eye will be damaged if you observe exploding Betelgeuse through a telescope with an area $sim 3,700$ larger — or roughly 60 times wider — than your pupil. In bright light, the pupil contracts to roughly 3 mm in diameter, so if observing through a telescope of 18 cm or larger, you could damage your eye.
Based on evolutionary models of Betelgeuse, Dolan et al. (2016) estimate an apparent magnitude of $m=-12.4$, i.e. roughly 6 times brighter than our estimate. This would mean that you only need a 3 cm telescope to damage your eye.
However, as Mark writes in his answer, supernovae don't increase to their peak brightness in matters of seconds, but rather in matters days (roughly half a mag per day), so you have plenty of time to look away.
edited 16 hours ago
answered 2 days ago
pela
17k3661
17k3661
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
|
show 1 more comment
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
2
2
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
I'm not sure this is the right calculation. Betelgeuse subtends only a tiny angle, meaning that when it's in focus all its light is focused on effectively a single point on the retina, whereas the sun's light is spread over an area. I'd be surprised if that didn't make it dangerous when using a much smaller telescope.
– Nathaniel
23 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
Additionally, this answer assumes that the brightness of the sun is the minimum required to go blind. For a complete answer, we should probably consider how much brightness the human eye can withstand without being blinded. It could be the case that a much smaller telescope than the one you propose is sufficient.
– JBentley
18 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@Nathaniel Yes, you're right. I'm not sure what the completely correct approach would be. A point source — which when seen through the atmosphere would span a few square arcsec — would be much brighter, but damage only a tiny fraction of your eye.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
@JBentley That's true, that's an assumption. But considering that you can actually look at the Sun for a brief period of time without permanently damaging your eye, I think makes this threshold okay, at least for an order-of-magnitude estimate.
– pela
17 hours ago
1
1
I edited to take into account these very relevant comments.
– pela
16 hours ago
I edited to take into account these very relevant comments.
– pela
16 hours ago
|
show 1 more comment
up vote
3
down vote
Brightness varies inversely with the square of the distance. Betelgeuse is about 642.5 light years away and has an apparent magnitude of 0.42. My grasp of apparent magnitude concepts is a bit wobbly, but I believe if it grew a million times as bright, it might have an apparent magnitude of -14.5 or so, which is a lot more like the brightness of the moon than the sun.
Given the great distance, the decrease in brightness due to distance, and the countless amounts of dust & gas between earth and Betelgeuse, I think you'd probably be fine. You might be dazzled by its brightness -- a bit like looking at a light bulb, I imagine -- but I doubt it would cause any physical harm.
EDIT: I hope a real astronomer sounds off here. I'm not sure what kind of supernova we might expect from Betelgeuse, but apparently supernovas (supernovae?) can achieve a theoretical brightness equal to 5 trillion suns!
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
add a comment |
up vote
3
down vote
Brightness varies inversely with the square of the distance. Betelgeuse is about 642.5 light years away and has an apparent magnitude of 0.42. My grasp of apparent magnitude concepts is a bit wobbly, but I believe if it grew a million times as bright, it might have an apparent magnitude of -14.5 or so, which is a lot more like the brightness of the moon than the sun.
Given the great distance, the decrease in brightness due to distance, and the countless amounts of dust & gas between earth and Betelgeuse, I think you'd probably be fine. You might be dazzled by its brightness -- a bit like looking at a light bulb, I imagine -- but I doubt it would cause any physical harm.
EDIT: I hope a real astronomer sounds off here. I'm not sure what kind of supernova we might expect from Betelgeuse, but apparently supernovas (supernovae?) can achieve a theoretical brightness equal to 5 trillion suns!
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
add a comment |
up vote
3
down vote
up vote
3
down vote
Brightness varies inversely with the square of the distance. Betelgeuse is about 642.5 light years away and has an apparent magnitude of 0.42. My grasp of apparent magnitude concepts is a bit wobbly, but I believe if it grew a million times as bright, it might have an apparent magnitude of -14.5 or so, which is a lot more like the brightness of the moon than the sun.
Given the great distance, the decrease in brightness due to distance, and the countless amounts of dust & gas between earth and Betelgeuse, I think you'd probably be fine. You might be dazzled by its brightness -- a bit like looking at a light bulb, I imagine -- but I doubt it would cause any physical harm.
EDIT: I hope a real astronomer sounds off here. I'm not sure what kind of supernova we might expect from Betelgeuse, but apparently supernovas (supernovae?) can achieve a theoretical brightness equal to 5 trillion suns!
Brightness varies inversely with the square of the distance. Betelgeuse is about 642.5 light years away and has an apparent magnitude of 0.42. My grasp of apparent magnitude concepts is a bit wobbly, but I believe if it grew a million times as bright, it might have an apparent magnitude of -14.5 or so, which is a lot more like the brightness of the moon than the sun.
Given the great distance, the decrease in brightness due to distance, and the countless amounts of dust & gas between earth and Betelgeuse, I think you'd probably be fine. You might be dazzled by its brightness -- a bit like looking at a light bulb, I imagine -- but I doubt it would cause any physical harm.
EDIT: I hope a real astronomer sounds off here. I'm not sure what kind of supernova we might expect from Betelgeuse, but apparently supernovas (supernovae?) can achieve a theoretical brightness equal to 5 trillion suns!
answered 2 days ago
S. Imp
1486
1486
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
add a comment |
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
1
1
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
Does it matter that the brightness comparable to the moon will be concentrated in a star-sized point?
– Barmar
yesterday
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I am not qualified to say. I will speculate that its intensity will be diffused quite a bit by all the dust & gas between us and Betelgeuse -- it's 640 light-years away. On the other hand, the moon looks extremely bright in my own telescope. Bright enough to dazzle the eyes quite a bit.
– S. Imp
13 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
I assumed you'd already included the diffusion in your estimate of the apparent magnitude.
– Barmar
12 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
My calculation was a simple one. I simply assumed that Betelgeuse might increase in brightness by a million, and converted that increase to apparent magnitude. Check the third paragraph here. This sort of sidesteps complicated diffusion calculations by just assuming diffusion will not change if the thing gets brighter.
– S. Imp
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
That seems like a reasonable assumption for broad estimates like this. In reality, diffusion is probably dependent on light wavelength, which I assume changes during supernova. But if we're just dealing with orders of magnitude, it's probably not significant.
– Barmar
11 hours ago
add a comment |
up vote
0
down vote
Funnily enough I was watching a video about this yesterday.
Although it would be very bright it would not reach anywhere near the brightness of the sun. It would probably rival the moon.
Worth watching:
https://www.youtube.com/watch?v=hJPVuSNFxlY
New contributor
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
add a comment |
up vote
0
down vote
Funnily enough I was watching a video about this yesterday.
Although it would be very bright it would not reach anywhere near the brightness of the sun. It would probably rival the moon.
Worth watching:
https://www.youtube.com/watch?v=hJPVuSNFxlY
New contributor
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
add a comment |
up vote
0
down vote
up vote
0
down vote
Funnily enough I was watching a video about this yesterday.
Although it would be very bright it would not reach anywhere near the brightness of the sun. It would probably rival the moon.
Worth watching:
https://www.youtube.com/watch?v=hJPVuSNFxlY
New contributor
Funnily enough I was watching a video about this yesterday.
Although it would be very bright it would not reach anywhere near the brightness of the sun. It would probably rival the moon.
Worth watching:
https://www.youtube.com/watch?v=hJPVuSNFxlY
New contributor
New contributor
answered yesterday
theblitz
1091
1091
New contributor
New contributor
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
add a comment |
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
5
5
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Note that the video also contains some poor quality info. For example, the reason a type II SN (the kind being described) happens is * not * because "the core becomes massive" (Betelgeuse's core at the time of collapse is no more massive than the previous period of time when it wasn't imploding). It's because fusion ceases after silicon/iron/nickel, which causes a partial loss of support. in a medium/small star that's fine, but in a star with a large enough core, the part-loss of support can be more than the core can handle . But the gist of it related to human impact is correct.
– Stilez
yesterday
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
Your answer is in another castle Please add the relevant facts here.
– Jan Doggen
23 hours ago
2
2
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
– Jan Doggen
23 hours ago
add a comment |
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4
"When it goes ..." - It's 642.5 light years away, so it would need to have already gone supernova over 550 years ago ... But we know what you meant, and Mark's answer is OK, as is the other.
– Rob
2 days ago
10
@Rob Depends on your reference frame ;) ( en.wikipedia.org/wiki/Relativity_of_simultaneity )
– jpa
yesterday