Timeline for How can we know if a star which is visible in our night sky goes supernova?
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12 events
| when toggle format | what | by | license | comment | |
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| Sep 17, 2021 at 4:54 | comment | added | James K | Gravitation lensing can delay, It can't shorten the light path. So it can't allow you to know if a 3000ly star has exploded, lensing doesn't change the answer to the question | |
| Sep 16, 2021 at 22:06 | comment | added | Taemyr | I am not sure about this answer. While information travels at the speed of light, it is not given that path lengths are equal. For example we expect light from the supernova of MRG-M0138 to be reach us close to 2037. - Of course 3000ly is far to close for these kinds of gravitational lensing to occur. | |
| Sep 16, 2021 at 20:22 | comment | added | PM 2Ring | (cont) Unfortunately, our present neutrino detectors are too crude and insensitive to get that kind of detailed neutrino data from distant stars. It's hard enough just detecting the solar neutrinos produced by various reactions. There's some good info about neutrino production in stars that are fusing heavier elements here. Also see the PEP reaction | |
| Sep 16, 2021 at 20:17 | comment | added | PM 2Ring | @Roger There's plenty of interesting neutrino action a few hours before a core-collapse becomes visible, but my 1st comment was about getting neutrino data that would tell us about the various reactions in the star core. If you know the star's mass and which heavier elements (like neon, oxygen, and magnesium) it's fusing, you can make a good estimate of how long it has left before it starts fusing silicon. | |
| Sep 16, 2021 at 20:00 | comment | added | PM 2Ring | @PeterErwin True, but for a Type Ia candidate, we want data about what's happening on the outside of the star. We want to know what's going on with the matter it's accreting from its companion, and how their orbits are evolving. | |
| Sep 16, 2021 at 19:41 | history | edited | Glorfindel | CC BY-SA 4.0 |
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| Sep 16, 2021 at 17:27 | comment | added | James K | @PeterErwin We can get the "hours warning" of a supernova. What we can't get is the 3000 year warning, by noting that neutrino emmision are consistent with fusion of (perhaps) neon and magnesium. | |
| Sep 16, 2021 at 11:05 | comment | added | Peter Erwin | Note that looking for increasing neutrino emissions as a forecast of an imminent supernova won't work for Type Ia supernovae, since they're not core-collapse objects. | |
| Sep 16, 2021 at 8:28 | comment | added | Peter Erwin | @James K “we can't get that data with the kind of neutrino detectors on Earth.” Actually, we probably can, if it’s within a kpc or so. This paper estimates that the Japanese KamLAND detector could get advance warning of Betelgeuse going SN several hours (maybe several dozen hours) in advance, depending on things like the star’s exact mass and distance and how many nuclear reactors are running in Japan. | |
| Sep 16, 2021 at 8:16 | comment | added | Peter Erwin | @RogerLipscombe See astronomy.stackexchange.com/a/18424/7411 | |
| Sep 16, 2021 at 7:53 | comment | added | Roger Lipscombe | How much warning would the neutrinos actually give us (assuming we had the ability to detect them) before the supernova became visible? Minutes, hours, days? How much of a head start do they get? | |
| Sep 16, 2021 at 5:36 | history | answered | James K | CC BY-SA 4.0 |