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lifeonmercury
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Are there any stars in the solar neighborhood that orbit the galactic center in the opposite direction?
Not sure if this counts, it's a fun video with some corny music:lifeonmercury said:Are there any stars in the solar neighborhood that orbit the galactic center in the opposite direction?
None known, and no reason (that I know of) to expect that there might be.lifeonmercury said:Are there any stars in the solar neighborhood that orbit the galactic center in the opposite direction?
These are 'wandering stars', which in greek is asteria planetes, from which the English word 'planets' derives.lifeonmercury said:What about stars with retrograde rotation (like Venus and Uranus)?
lifeonmercury said:Sorry for the confusion. I understand the difference between retrograde orbit and retrograde rotation. After my original question was answered that there are no known stars in the Milky Way with a retrograde orbit, I then asked if any stars have a retrograde rotation.
Interesting! From Wikipedia's article Retrograde and prograde motion:glappkaeft said:There are however billions of stars in retrograde galactic orbits in the milky way, most of them are in the halo, in-falling star streams from dwarf galaxies being absorbed or in the galactic bulge. They are mostly tens or hundreds of thousand light years away from Earth but at just 12 ly one star that is hard to exclude is the M1 sub-dwarf Halo star known as Kapteyn's Star (A&A paper).
Stars with a retrograde orbit are more likely to be found in the galactic halo than in the galactic disk. The Milky Way's outer halo has many globular clusters with a retrograde orbit and with a retrograde or zero rotation.
I'm merely speculating here, but I guess a galactic collision between a big galaxy like ours and a much smaller galaxy (so that the big galaxy does not lose it's individuality) could produce retrograde motions of stars.lifeonmercury said:Are there any stars in the solar neighborhood that orbit the galactic center in the opposite direction?
lifeonmercury said:A star that is tidally locked with the galactic center is also possible I suppose.
While technically correct, it hides the causal order. The Milky Way started with gas clouds with a random total angular momentum, which then assembled to a disk over time based on collisions between gas clouds. Those clouds then formed the stars in the disk with prograde motion. Stars with retrograde motion were captured from outside or got their motion from violent events in binary systems (e. g. their partner star exploded in a supernova) or similar events.Stars with a retrograde orbit are more likely to be found in the galactic halo than in the galactic disk.
Retrograde star orbits, where the star moves in the opposite direction of the majority of stars in the galaxy, are relatively rare in the Milky Way. Only about 5% of stars in our galaxy have a retrograde orbit.
There are a few different factors that can contribute to a star having a retrograde orbit. One possibility is that the star was captured by the gravitational pull of a larger object, such as a black hole or a passing galaxy, causing it to change its orbit. Another possibility is that the star formed from a collision between two smaller stars, resulting in a retrograde orbit.
No, retrograde stars can have a variety of orbit patterns. Some may have highly eccentric orbits, while others may have a more circular orbit. The specific orbit pattern depends on the initial conditions and any interactions with other objects in the galaxy.
It is possible for retrograde star orbits to be stable, but it depends on a variety of factors. If the star is in a binary system, its orbit may be more stable due to the gravitational influence of its companion star. However, if the star is in a crowded region of the galaxy, interactions with other objects may disrupt its orbit over time.
Yes, retrograde star orbits have been observed in other galaxies as well. In fact, some galaxies have a higher percentage of retrograde stars compared to our Milky Way. This can provide valuable insights into the formation and evolution of galaxies and their stars.