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Astronomers Discover Closest Black Hole to Earth
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- abhaynayar 4y agoI guess I was wrong then. https://news.ycombinator.com/item?id=31381169 https://news.ycombinator.com/item?id=31381169
- PartiallyTyped 4y agoUnless there's proof that the last planet is indeed... well... a planet; we that can't be ruled out just yet :D
- Eupraxias 4y agoThey calculate that it is 1600 light years away. So, unless you were lighting your childhood campfires 1600 years ago, that light still has a little way to go.
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- habibur 4y agoThe numbers : Size : 10 x sun's mass. Distance : 1600 LY. Previous closest had been : ~5000 LY. Discovered by calculating the velocity of a rotating run around it. For comparison, a star going supernova to harm earth has be to within 70 LY.
- 867-5309 4y ago>For distance comparison, a star going supernova to harm earth has be to within 70 LY. what is that based on?
- Smashure 4y agoI don’t know where they got that number from. It’s depending on a multitude of factors like, type of supernova and orientation of the supernova (like if we’re in line for a gamma ray burst) *edit For anyone interested in this topic I suggest Phil Plait’s book in the subject
- pencilguin 4y agoI think 5 ly is the range for a supernova sterilizing the solar system if we are not so unlucky to be in a jet. 500 ly is supposed to be equivalent range for a magnetar quake. I think the nearest known magnetar is around 10x that. But even 1% of the radiation needed to sterilize the solar system would be pretty uncomfortable.
- bilsbie 4y agoAny risks of that within 70ly?
- ceejayoz 4y agoNot at the moment. IK Pegasi is the closest candidate, at about 2x that distance. Would be a hell of a show, though. https://en.wikipedia.org/wiki/Near-Earth_supernova https://en.wikipedia.org/wiki/Near-Earth_supernova
- dtgriscom 4y agoDoes that make the assumption that the nova's energy is distributed evenly? Because I believe there are gamma ray bursts that are quite directional, and can if pointed at us cause harm far further than that. (IANA astronomer...)
- colechristensen 4y agoNo, a gamma ray burst pointed at us within several thousand light years could cause a mass extinction event. There are a couple of candidates for mass extinctions which might have been GRBs. They are very rare though.
- pencilguin 4y agoStill, it would be safer to get out of the thick part of the galaxy as soon as possible. Life in a galaxy risks many different hazards. I don't think we have ruled out magnetars nearby enough that a minor starquake would sterilize the whole solar system. Aggressive neighbors might want to use up our valuable Kuiper Belt objects on their own projects. Maybe start by shifting the orbit of the whole solar system out-of-plane. (I guess that would be done by electromagnetically stimulating the sun to produce a polar jet for a few million years.) That provides our distant descendants another 100M years to alter the orbit further so as not to just plunge back in on the other side. But even without, the risk would grow back to our present level for only (say) 10M out of each 100M years, strictly an improvement. Orbital plane maneuvers are infamously expensive in delta-V. Spending the following 100M years increasing our galactic orbital radius might put us in the outskirts before crossing again, if we did not actually escape entirely. We might also be able to put off by a few billion years the sun itself sterilizing the planet, using the same apparatus. We could only hope it would not be abused to destroy us itself. Andromeda isn't due for another 4.5 Gy. Presumably its central black hole and ours will merge shortly thereafter, maybe sterilizing the whole galaxy? I am content to leave worrying about that to others.
- dustingetz 4y agohow wide is the event horizon and how close can a current gen spaceship get before being gravitationally bound?
- Hobert 4y agoAbout 1600LY...
- derjames 4y agoSchwarzschild radius ~28 km https://en.wikipedia.org/wiki/Gaia_BH1 https://en.wikipedia.org/wiki/Gaia_BH1
- sabujp 4y agotx this is what i was looking for, also this agrees https://www.omnicalculator.com/physics/schwarzschild-radius https://www.omnicalculator.com/physics/schwarzschild-radius
- Simon_O_Rourke 4y agoThanks guys, another worry to add to the list of climate change, potential right-wing insurrection and the health effects of Taco Bell.
- spuz 4y ago> Astronomers' current models of the evolution of binary systems cannot fully explain how the peculiar configuration of the Gaia BH1 system came about, because the original star that later became this black hole should have been at least 20 times more massive than our Sun. This means that it would have lived only a few million years. If both stars formed at the same time, this massive star would have rapidly become a supergiant, inflating and engulfing the other star before it had time to become a proper main-sequence star, burning hydrogen just like our own Sun. > It's not entirely clear how the solar-mass star survived that episode, ending up an apparently normal star, as observations indicate. All theoretical models that allow for this survival predict that the solar-mass star should be in a much tighter orbit than is actually observed. Should this last sentence actually read: "All theoretical models that allow for this survival predict that the solar-mass star should be in a much wider orbit than is actually observed."?
- Broken_Hippo 4y agoMaybe, but I'll give some slack here. Translations aren't perfect and maybe it read better before translation.
- tete 4y agoWhy? It's just the closest detected one.
- Broken_Hippo 4y agoOk. So? The issue here is that I don't read spanish. I used a translator - google, actually. And I know painfully well that sometimes translations are clunky even when they are generally good. I don't have a lot of experience between Spanish and English, but I do with Norwegian-English, and those are both germanic languages and often translate decently. But not always. Some things are just messed up. Some things don't translate word-for-word simply because folks express things differently. So yeah, it might be weird in English. Might not be in Spanish, though.
- narag 4y ago
- _justinfunk 4y agoCloset black hole to earth so far
- dylan604 4y agoRight. Just wait until they turn on the Large Hadron Collider and it starts to create black holes that will swallow the earth! /s
- aaron695 4y ago
- delta_p_delta_x 4y agoActual article: https://doi.org/10.1093/mnras/stac3140 https://doi.org/10.1093/mnras/stac3140
- amacbride 4y agoEnglish version from the same site: https://noirlab.edu/public/news/noirlab2227/?nocache=true https://noirlab.edu/public/news/noirlab2227/?nocache=true
- pencilguin 4y agohttps://noirlab.edu/public/news/noirlab2227/?lang=en https://noirlab.edu/public/news/noirlab2227/?lang=en It says "Though there are likely millions of stellar-mass black holes roaming the Milky Way..." I thought it was billions, now.
- JoeAltmaier 4y agoExcept maybe a tiny one in the middle of the Sun or even the Earth?
- midislack 4y ago* Closest KNOWN black hole to Earth. Not the closest one, period.
- westurner 4y agoMicro black hole > Black holes in quantum theories of gravity https://en.wikipedia.org/wiki/Micro_black_hole#Black_holes_in_quantum_theories_of_gravity https://en.wikipedia.org/wiki/Micro_black_hole#Black_holes_i... Virtual black hole https://en.wikipedia.org/wiki/Virtual_black_hole https://en.wikipedia.org/wiki/Virtual_black_hole Timeline of gravitational physics and relativity https://en.wikipedia.org/wiki/Timeline_of_gravitational_physics_and_relativity https://en.wikipedia.org/wiki/Timeline_of_gravitational_phys... - [ ] Superfluid Quantum Gravity -- [ ] GR + Bernoulli's re: Dark Matter/Energy: Fedi (2017), "What If (Tiny) Black Holes Are Everywhere?" https://youtu.be/srVKjWn26AQ https://youtu.be/srVKjWn26AQ > Just one Planck relic per 30km cube, and that’s enough to make up most of the mass in the universe Quantum foam: https://en.wikipedia.org/wiki/Quantum_foam https://en.wikipedia.org/wiki/Quantum_foam