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zuz
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The closest star tp the sun is 4 light years away. Are there any stars that are closer that are not part of a multi=star system? How close close can stars get to each other and still be independent systems?
No.zuz said:The closest star tp the sun is 4 light years away. Are there any stars that are closer that are not part of a multi=star system?
In theory, they can get close enough to distort each other and still be independent - if it were a flyby on a hyperbolic path.zuz said:How close close can stars get to each other and still be independent systems?
With the exception one little part, they aren't really being compared, they are simultaneous but separate criteria. Reading between the lines, the answer would be there is no limit. A follow up might be; what has been observed?Vanadium 50 said:"Independent systems" is a statement about velocity and gravitational binding. "Close" is a statement about position. They cannot be directly compared.
russ_watters said:Reading between the lines, the answer would be there is no limit.
The OP isn't asking about theory, he's asking about reality. Again, reading between the lines (I shouldn't have to), the answer I'm seeing is "arbitrarily close to zero". So, how close have we observed in reality? I suspect the answer due to the timing issue is not very close at all.Vanadium 50 said:If stars were points, that would be true. You tell me how close you want it, and I'll tell you how fast it needs to be going.
Have we observed stars that were not gravitationally bound collide? It must be an extremely rare thing to observe.Vanadium 50 said:Stars have collided. That's pretty close.
How independent? In fact what do you mean by the word? Orbits (two body) that are circular or elliptical could be called not independent but when the orbits are hyperbolic, the kinetic energy is greater than the potential energy at the closest point. A close approach perhaps but the two could be called independent.zuz said:still be independent systems?
"... the mean radial velocity has been determined to be around 22.4 km/s towards the Solar System."zuz said:Also, is the Centauri system moving toward or away from us? Thanks.
It’s less uncommon in globular clusters, where the density of stars is much greater.russ_watters said:Have we observed stars that were not gravitationally bound collide? It must be an extremely rare thing to observe
Vanadium 50 said:In that case, the minimum distance is zero because stars (rarely) collide.
No what?snorkack said:No,
So what?snorkack said:because can you point at observed star collision?
snorkack said:can you point at observed star collision?
As of present, we have catalogued ~200 million of the ~200 billion stars in our galaxy alone, or roughly 1/1000 them. Not seeing a remnant of a star collision in those catalogued stars merely puts an upper limit on the number of star collisions that could have occurred in the galaxy but does not eliminate their existence entirely. (so for example, if there is, on average, 1 collision per 100 million years or so, then our galaxy might have 130 collision remnants and the odds of one of those being in our 200 million star sample are fairly low. )snorkack said:No, because can you point at observed star collision?
Not a blue straggler suspected to have formed by collision some time before observation (and it is argued whether blue stragglers might form by inspiral of binaries previously bound) - no, actual observed collision, constellation, year, date, properties of each precursor and resulting star?
And even that would not be distance between two stars right now because a past observed collision is one star now. Are there any stars observed on collision course that are now unbound (not on inspiral course)?
snorkack said:There have been a number of observed inspirals in a few years.
Janus said:Not seeing a remnant of a star collision in those catalogued stars merely puts an upper limit on the number of star collisions that could have occurred in the galaxy but does not eliminate their existence entirely.
Can we determine the cause of a collision when we look at remnants? For example CK Vulpeculae, can we be sure that was a binary merger? I realize that the odds of a binary merging are much much higher than a random impact. What would look different if the rare event did take place?Janus said:As of present, we have catalogued ~200 million of the ~200 billion stars in our galaxy alone, or roughly 1/1000 them. Not seeing a remnant of a star collision in those catalogued stars merely puts an upper limit on the number of star collisions that could have occurred in the galaxy but does not eliminate their existence entirely. (so for example, if there is, on average, 1 collision per 100 million years or so, then our galaxy might have 130 collision remnants and the odds of one of those being in our 200 million star sample are fairly low. )
Lack of evidence is not always evidence of lack.
Yes, a great deal of brightening. Then the source should be snuffed out by dust and clouds.snorkack said:...
Do collisions between main sequence stars cause any brightening?
stefan r said:Even if two stars completely missed and did not exchange material there should be some strong tidal effects.
Nitpick: the above passage seems to suggest that a meteor's velocity is in large part due to falling.stefan r said:Meteors are white hot even though they are just falling into Earth's gravity.
Epsilon Aurigae is a binary star system located in the constellation Auriga. It is composed of a bright, hot star and a dim, cooler star that orbit each other. The system is approximately 2,000 light years away from Earth.
A mysterious eclipse in Epsilon Aurigae refers to a period of time when the brighter star in the system is partially or completely blocked from view by the dimmer star. This eclipse occurs every 27 years and lasts for about 2 years, making it longer than any other known eclipse in the universe.
The eclipses in Epsilon Aurigae are caused by the orbit of the dimmer star, which is surrounded by a large, disk-shaped cloud of dust and gas. This disk blocks the light from the brighter star, creating the eclipse.
The eclipses in Epsilon Aurigae are considered mysterious because the exact nature and composition of the disk surrounding the dimmer star is still unknown. Scientists have been studying this system for decades, but there is still much to be learned about the cause of these eclipses.
Scientists use a variety of methods to study the eclipses in Epsilon Aurigae, including observing the system with telescopes, analyzing the light spectrum of the stars, and creating computer models to simulate the eclipses. They also collaborate with other scientists and use data from previous eclipses to gather more information about this intriguing phenomenon.