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So that's actually further away than the closest star systems. Got freaked out for a second, because having hard-to-see massive objects near your sun system is

So that's actually further away than the closest star systems. Got freaked out for a second, because having hard-to-see massive objects near your sun system is scary!

mynegation 6y ago
Nearest known brown dwarf (actually a binary) Luhman-16 is farther away than Proxima but not by much (relatively speaking). It would be interesting to know if a theoretical smallest coolest brown dwarf would be detectable with the current technology.
- skykooler 6y ago
  The line between small brown dwarfs and large planets is blurry. A brown dwarf twice the size of Jupiter and twelve times its mass could probably get inside our Oort cloud and have evaded detection.
garmaine 6y ago
Why would it be scary?
- ivalm 6y ago
  If a brown dwarf scatters into the solar system it might dramatically shift orbits potentially making earth uninhabitable. To say nothing of a direct hit on anything, even hitting the sun might strip atmosphere from earth, hitting any planet would create world ending debris fields
- jvm___ 6y ago
  Because eventually that body would have gravitational effects on our stable system and could throw everything out of whack.
  - garmaine 6y ago
    If it were in our solar system then it would be in a gravitationally stable arrangement--because if it weren't it would have already thrown things out of whack in the last 4.5 billion years.
  - kabdib 6y ago
    The solar system is actually not stable in the long term. Early planetary development was violent and chaotic, and the planets shifted around a lot more than you might think. We can't project orbits out indefinitely, either; multiple studies show that our ability to go out more than a few hundred million years are suspect and very dependent on starting conditions, which can obviously be easily perturbed by unknown bodies. Since we get star-sized approaches at Oort Cloud distances on the order of every few million years, that probably puts an upper bound on things.
    - btilly 6y ago
      Our next such approach is https://en.wikipedia.org/wiki/Gliese_710 https://en.wikipedia.org/wiki/Gliese_710 in 1.281 million years. However the rate at which such encounters happen varies greatly. We are in an orbit bobs up and down from the galactic ecliptic with a period of roughly 60 million years. There are more encounters near the ecliptic, with very few encounters when we are above or below. We cross the ecliptic about every 30 million years, and last did so about 3 million years ago. So we are still in the dangerous period. It is not entirely a coincidence that the dinosaurs were wiped out 66 million years ago, during another relatively dangerous period.
- adenozine 6y ago
  Could be an object at high speed, waiting for the right gravity assist directly into us? Could be a strange object with capability to disrupt the sun somehow? Why would an object hitherto unbeknownst to us and close to the sun NOT be scary?
  - garmaine 6y ago
    > Could be an object at high speed, waiting for the right gravity assist directly into us? An object larger than Jupiter doesn't change its course because of chance encounters with other random small bodies. > Could be a strange object with capability to disrupt the sun somehow? This doesn't make physical sense. > Why would an object hitherto unbeknownst to us and close to the sun NOT be scary? Because it's had no observable effect on us for the last 4.5 billion years of our solar system's existence, and we've postulated nothing that would change this stable dynamical relationship?
    - adenozine 6y ago
      Then I guess the morons with careers in astrophysics are investigating it for no reason then. Beyond your wildly unfounded and I daresay naive assumption that the objects have had no effect on the solar system, perhaps they need to hear YOUR postulations. If only they were reading all of your grayed out comments, I see your dismissive and arrogant condescending remarks are leading to such fruitful insights and conversations. /s Feel better soon
      - thombat 6y ago
        New things are interesting, and astrophysicists like investigating interesting things. If these brown dwarfs posed the slightest threat to us they'd be even more interesting than they already are.
        adenozine 6y ago
        Sure, I guess it's just irksome to assume that they aren't dangerous PRIOR to investigation. I mean, you wouldn't assume a random plant in the jungle is safe to eat, right? There's a lot of safe objects in space. There's a lot of safe plants in the jungle. Still, truth must be uncovered day by day. That's all I was meaning to convey.
- wcoenen 6y ago
  In the scifi short story "a pail of air", the Earth is yanked away from the Sun by a dark star passing through the solar system. The Earth cools until all of the atmospheric gasses turn into solids and fall to the ground as layers of ultra-cold snow. It's one of the pieces of fiction that left a deep impression on me. Harsh winter days still remind me of it. http://www.gutenberg.org/ebooks/51461 http://www.gutenberg.org/ebooks/51461
  - garmaine 6y ago
    I suggest basing your view of reality on facts, not fiction.
    - Rebelgecko 6y ago
      The fact is that 250 light-years is not "near" the sun. Unless you're an astronomer, there's no practical difference between something that is 2 light years or 2,000,000 light years away. Both distances are equally unattainable. Saying that something is near "the sun" (as opposed to a more generic area like "the solar system") makes it sound like it's much closer than it actually is. Imagine if the article said that the stars were near "Dallas Texas". It would be equally true (±0.001%), but IMO the extra specificity is misleading
      - FalconSensei 6y ago
        Exactly. They are not specifically near 'our sun'. They are near our system. The title (because of the specificity), seems to say that they are in our solar system, or so close that you could consider it like that
        waheoo 6y ago
        Yup, super weird sentence. It reads as if it is either between us and the sun, or close enough that you'd see it roughly up to the same distance we are from the sun.
    - samatman 6y ago
throwaway316943 6y ago
Don’t worry, there could still be somewhat smaller less detectable objects nearby.

So that's actually further away than the closest star systems. Got freaked out for a second, because having hard-to-see massive objects near your sun system is scary!

mynegation 6y ago

Nearest known brown dwarf (actually a binary) Luhman-16 is farther away than Proxima but not by much (relatively speaking). It would be interesting to know if a theoretical smallest coolest brown dwarf would be detectable with the current technology.

skykooler 6y ago
The line between small brown dwarfs and large planets is blurry. A brown dwarf twice the size of Jupiter and twelve times its mass could probably get inside our Oort cloud and have evaded detection.

garmaine 6y ago

Why would it be scary?

ivalm 6y ago
If a brown dwarf scatters into the solar system it might dramatically shift orbits potentially making earth uninhabitable. To say nothing of a direct hit on anything, even hitting the sun might strip atmosphere from earth, hitting any planet would create world ending debris fields
jvm___ 6y ago
Because eventually that body would have gravitational effects on our stable system and could throw everything out of whack.
- garmaine 6y ago
  If it were in our solar system then it would be in a gravitationally stable arrangement--because if it weren't it would have already thrown things out of whack in the last 4.5 billion years.
- kabdib 6y ago
  The solar system is actually not stable in the long term. Early planetary development was violent and chaotic, and the planets shifted around a lot more than you might think. We can't project orbits out indefinitely, either; multiple studies show that our ability to go out more than a few hundred million years are suspect and very dependent on starting conditions, which can obviously be easily perturbed by unknown bodies. Since we get star-sized approaches at Oort Cloud distances on the order of every few million years, that probably puts an upper bound on things.
  - btilly 6y ago
    Our next such approach is https://en.wikipedia.org/wiki/Gliese_710 https://en.wikipedia.org/wiki/Gliese_710 in 1.281 million years. However the rate at which such encounters happen varies greatly. We are in an orbit bobs up and down from the galactic ecliptic with a period of roughly 60 million years. There are more encounters near the ecliptic, with very few encounters when we are above or below. We cross the ecliptic about every 30 million years, and last did so about 3 million years ago. So we are still in the dangerous period. It is not entirely a coincidence that the dinosaurs were wiped out 66 million years ago, during another relatively dangerous period.
adenozine 6y ago
Could be an object at high speed, waiting for the right gravity assist directly into us? Could be a strange object with capability to disrupt the sun somehow? Why would an object hitherto unbeknownst to us and close to the sun NOT be scary?
- garmaine 6y ago
  > Could be an object at high speed, waiting for the right gravity assist directly into us? An object larger than Jupiter doesn't change its course because of chance encounters with other random small bodies. > Could be a strange object with capability to disrupt the sun somehow? This doesn't make physical sense. > Why would an object hitherto unbeknownst to us and close to the sun NOT be scary? Because it's had no observable effect on us for the last 4.5 billion years of our solar system's existence, and we've postulated nothing that would change this stable dynamical relationship?
  - adenozine 6y ago
    Then I guess the morons with careers in astrophysics are investigating it for no reason then. Beyond your wildly unfounded and I daresay naive assumption that the objects have had no effect on the solar system, perhaps they need to hear YOUR postulations. If only they were reading all of your grayed out comments, I see your dismissive and arrogant condescending remarks are leading to such fruitful insights and conversations. /s Feel better soon
    - thombat 6y ago
      New things are interesting, and astrophysicists like investigating interesting things. If these brown dwarfs posed the slightest threat to us they'd be even more interesting than they already are.
      - adenozine 6y ago
        Sure, I guess it's just irksome to assume that they aren't dangerous PRIOR to investigation. I mean, you wouldn't assume a random plant in the jungle is safe to eat, right? There's a lot of safe objects in space. There's a lot of safe plants in the jungle. Still, truth must be uncovered day by day. That's all I was meaning to convey.
wcoenen 6y ago
In the scifi short story "a pail of air", the Earth is yanked away from the Sun by a dark star passing through the solar system. The Earth cools until all of the atmospheric gasses turn into solids and fall to the ground as layers of ultra-cold snow. It's one of the pieces of fiction that left a deep impression on me. Harsh winter days still remind me of it. http://www.gutenberg.org/ebooks/51461 http://www.gutenberg.org/ebooks/51461
- garmaine 6y ago
  I suggest basing your view of reality on facts, not fiction.
  - Rebelgecko 6y ago
    The fact is that 250 light-years is not "near" the sun. Unless you're an astronomer, there's no practical difference between something that is 2 light years or 2,000,000 light years away. Both distances are equally unattainable. Saying that something is near "the sun" (as opposed to a more generic area like "the solar system") makes it sound like it's much closer than it actually is. Imagine if the article said that the stars were near "Dallas Texas". It would be equally true (±0.001%), but IMO the extra specificity is misleading
    - FalconSensei 6y ago
      Exactly. They are not specifically near 'our sun'. They are near our system. The title (because of the specificity), seems to say that they are in our solar system, or so close that you could consider it like that
      - waheoo 6y ago
        Yup, super weird sentence. It reads as if it is either between us and the sun, or close enough that you'd see it roughly up to the same distance we are from the sun.
  - samatman 6y ago

throwaway316943 6y ago

Don’t worry, there could still be somewhat smaller less detectable objects nearby.