The Milky Way galaxy moves within the Local Group, which is gravitationally bound and orbits a common center. Unlike the circular motion of the sun around the Milky Way's center, the dynamics of galaxies in the Local Group are more complex due to their larger sizes and interactions. These interactions can lead to phenomena such as galaxies ripping each other apart, indicating that their motion isn't simply elliptical. The mass distribution within the Local Group complicates the understanding of galaxy movements, suggesting they may not follow traditional orbital patterns. Overall, the Milky Way's movement is influenced by its gravitational relationships with other galaxies in the Local Group.
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abdossamad2003
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How does the Milky Way galaxy move in the local Group? Is there a circular motion around the center of the local Group like the sun moves around the center of the galaxy?
I believe the Local Group is gravitationally bound, so there is a common center about which its mass must collectively orbit. However, the group is only about 100 times the diameter of the Milky Way, so galaxies are much larger in comparison to the spaces between them than stars are, so they interact in more complex ways than stars typically do - ripping each other apart, for example.
All that means that I think you have a mass distribution that isn't really well described as a fluid (like a galaxy) or a collection of point masses orbiting one (like a solar system). So I would suspect that galaxy motions aren't pure ellipses, because they interact a lot (and there are definitely satellite galaxies of the Milky Way). But I am not certain.
Partial solar eclipse from Twizel, South Isl., New Zealand ...
almost missed it due to cloud, didnt see max at 0710 NZST as it went back into cloud.
20250922, 0701NZST
Canon 6D II 70-200mm @200mm,
F4, 100th sec, 1600ISO
Makeshift solar filter made out of solar eclipse sunglasses
Today at about 4:30 am I saw the conjunction of Venus and Jupiter, where they were about the width of the full moon, or one half degree apart. Did anyone else see it?
Edit: The moon is 2,200 miles in diameter and at a distance of 240,000 miles. Thereby it subtends an angle in radians of 2,200/240,000=.01 (approximately). With pi radians being 180 degrees, one radian is 57.3 degrees, so that .01 radians is about .50 degrees (angle subtended by the moon). (.57 to be more exact, but with...
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed).
n.b. I start this...