Starship Asterisk*

Guest wrote:
Just curious. The frame is mentioned as covering a diameter of 12 LY. Based on the image, this would put the most energetic part of the "bowshock" a light year from the star...how is there enough particle density, or radiation pressure...or combination of both, to produce this at this distance?

• Zeta Oph is 65,000 times more luminous than the Sun so it's radiation pressure
  (dropping off with the square of the distance) extends out ~ 250 times as far.
  
  However, really, it is caused by stellar-wind pressures ~ 65,000 times that of the sun:

https://en.wikipedia.org/wiki/Stellar-wind_bubble wrote:
<<Stellar-wind bubble is the astronomical term usually used to describe a cavity light years across filled with hot gas blown into the interstellar medium by the high-velocity (several thousand km/s) stellar wind from a single massive star of type O or B. Weaker stellar winds still blow bubble structures though, and these are also called astrospheres. The heliosphere blown by the solar wind, within which all the major planets of the Solar System are embedded, is a small example of a stellar-wind bubble.

Stellar-wind bubbles have a two-shock structure. The freely-expanding stellar wind hits an inner termination shock, where its kinetic energy is thermalized, producing 10⁶ K, X-ray emitting plasma. The hot, high-pressure, shocked wind expands, driving a shock into the surrounding interstellar gas. If the surrounding gas is dense enough (number densities or so), the swept up gas radiatively cools far faster than the hot interior, forming a thin, relatively dense shell around the hot, shocked wind.

geckzilla wrote:I imagine it'll arc in orbit around the galaxy, escaping from its previous orbit with another star, but not the galaxy itself. Does it have enough time to make an orbit or two before it explodes? Maybe, maybe not...

DavidLeodis wrote:The picture of the cat brought up through the "relatively undisturbed" link made me . It may be thinking I'll have time for a cat nap as this internet connection is so slow! It may of course be wondering why the tab function is acting very oddly and why are all the onscreen letters in capitals? Perhaps it's a tabby cat .

neufer wrote:

Guest wrote:
Is it going to keep moving indefinitely to the left?

Until it ends its life in a supernova explosion in a few million years
(i.e., a few hundred more light years to the left) leaving behind a left moving Neutron Star.

Guest wrote:
Is it going to keep moving indefinitely to the left?

Guest wrote:
Is there any way to detect how far it's traveled from its origin point within the theorized binary star system?

https://en.wikipedia.org/wiki/Zeta_Ophiuchi wrote:
<<ζ Ophiuchi is a young star with an age of only three million years. Based upon the age and direction of motion of this star, it is a member of the Upper Scorpius sub-group of the Scorpius-Centaurus Association of stars that share a common origin and space velocity. Such runaway stars may be ejected by dynamic interactions between three or four stars. However, in this case the star may be a former component of a binary star system in which the more massive primary was destroyed in a Type II supernova explosion. The pulsar PSR B1929+10 may be the leftover remnant of this supernova, as it too was ejected from the association with a velocity vector that fits the scenario.>>

Dad is watching wrote:In the description, it says that the star was 'flung out of the system' from a binary pair. Just so we understand it, has the correct terminology been used? Or would it be more accurate to say that the star escaped from the system because of preexisting momentum. If the star was actually flung (throw or hurl forcefully), would that imply some sort of 'gravity assist' as the smaller star fell in to the gravity well of the larger companion and was subsequently ejected?

the old blind man wrote:The picture is sorely missing a star trek imperial cruiser getting in between the star and the nebula at full speed and disturbing the dust on the left in the process.

Guest wrote:
How accurately does one know the transverse motion of this star?

• In it's 4 years of operation the Hipparcos satellite
  (with an operational accuracy of ~1 milliarcsecond) had no problem
  tracking the rapid 29 mas/yr transverse motion of ζ Ophiuchi.

Guest wrote:How accurately does one know the transverse motion of this star? I have seen this comment before. It is unfounded.