4 ms·

Hypervelocity stars

30 points by craneca0 11y ago

m_mueller 11y ago
At that point, slowing down to the trajectory of a normal solar system might be the biggest problem for a space ship launched from there.
- DiabloD3 11y ago
  How would the g-forces of being on a planet, or even being the planet itself, in orbit of such a star, work?
  - 78666cdc 11y ago
    There will be no additional g-forces if there is no acceleration, regardless of velocity. The related concept is that of an inertial reference frame.
    - deleted 11y ago
      [deleted]
  - mey 11y ago
    Your reference frame[1] would negate most effect until you get really close to the speed of light. Like we don't notice that we're orbiting the sun at 66,135 mph [2] or that we're also moving through the galaxy at almost 500,000 mph [3] - https://en.wikipedia.org/wiki/Frame_of_reference - http://www.wolframalpha.com/input/?i=how+fast+does+the+earth+orbit+the+sun - http://www.wolframalpha.com/input/?i=how+fast+is+the+sun+moving
    - gizmo686 11y ago
      Don't you still not experience any effects even if the whole system was travelling at relativistic speeds (relative to the galaxy).
      - m_mueller 11y ago
        You would experience time and length dilation of everything outside the star system.
  - m_mueller 11y ago
    After the actual acceleration there wouldn't be any difference to how life on such planets works. What's difficult for me to estimate is the likelihood of surviving the slingshot itself however. Looking at the closest known orbit around Sagittarius A* [1] you get an orbital acceleration of this star system of around 0.2G. I'm not entirely sure about the math, but I'd imagine the slinghot would have to keep an orbital acceleration of significantly less than the planet's own surface gravity, otherwise it would probably strip its atmosphere. [1] https://en.wikipedia.org/wiki/S2_%28star%29 https://en.wikipedia.org/wiki/S2_%28star%29
  - deleted 11y ago
    [deleted]
dstyrb 11y ago
I worked in this area briefly and I verify that this is actually a high quality article on the topic. The last one I read was a publicity ploy for a rushed job.
benihana 11y ago
Would the universe appear redshifted to an observer on a planet orbiting one of these stars?
- nitrogen 11y ago
  Blue in one direction, red in the other.
jakeogh 11y ago
Fun colloquium on hypervelocity stars: https://www.youtube.com/watch?v=SI0ePSHz5b4 https://www.youtube.com/watch?v=SI0ePSHz5b4

30 points by craneca0 11y ago

At that point, slowing down to the trajectory of a normal solar system might be the biggest problem for a space ship launched from there.

DiabloD3 11y ago
How would the g-forces of being on a planet, or even being the planet itself, in orbit of such a star, work?
- 78666cdc 11y ago
  There will be no additional g-forces if there is no acceleration, regardless of velocity. The related concept is that of an inertial reference frame.
  - deleted 11y ago
    [deleted]
- mey 11y ago
  Your reference frame[1] would negate most effect until you get really close to the speed of light. Like we don't notice that we're orbiting the sun at 66,135 mph [2] or that we're also moving through the galaxy at almost 500,000 mph [3] - https://en.wikipedia.org/wiki/Frame_of_reference - http://www.wolframalpha.com/input/?i=how+fast+does+the+earth+orbit+the+sun - http://www.wolframalpha.com/input/?i=how+fast+is+the+sun+moving
  - gizmo686 11y ago
    Don't you still not experience any effects even if the whole system was travelling at relativistic speeds (relative to the galaxy).
    - m_mueller 11y ago
      You would experience time and length dilation of everything outside the star system.
- m_mueller 11y ago
  After the actual acceleration there wouldn't be any difference to how life on such planets works. What's difficult for me to estimate is the likelihood of surviving the slingshot itself however. Looking at the closest known orbit around Sagittarius A* [1] you get an orbital acceleration of this star system of around 0.2G. I'm not entirely sure about the math, but I'd imagine the slinghot would have to keep an orbital acceleration of significantly less than the planet's own surface gravity, otherwise it would probably strip its atmosphere. [1] https://en.wikipedia.org/wiki/S2_%28star%29 https://en.wikipedia.org/wiki/S2_%28star%29
- deleted 11y ago
  [deleted]

dstyrb 11y ago

I worked in this area briefly and I verify that this is actually a high quality article on the topic. The last one I read was a publicity ploy for a rushed job.

benihana 11y ago

Would the universe appear redshifted to an observer on a planet orbiting one of these stars?

nitrogen 11y ago
Blue in one direction, red in the other.

jakeogh 11y ago

Fun colloquium on hypervelocity stars: https://www.youtube.com/watch?v=SI0ePSHz5b4 https://www.youtube.com/watch?v=SI0ePSHz5b4