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Are the stars orbiting the Milky way all orbiting at very different speeds then? If not, I would think the stellar environment of any star would remain relative
by arbuge 5y ago
Are the stars orbiting the Milky way all orbiting at very different speeds then? If not, I would think the stellar environment of any star would remain relatively constant over time.
- rbanffy 5y agoSpeeds (linear and angular) decrease the further we are from the center, so bodies near the center will orbit it in less time than us, who take less time to do a lap around the galaxy than stars further out.
- matt_kantor 5y agoActually the speeds of objects orbiting the center of galaxies first increase then quickly flatten out the further you get from the center: https://en.wikipedia.org/wiki/Galaxy_rotation_curve https://en.wikipedia.org/wiki/Galaxy_rotation_curve This is one piece of evidence for the existence of dark matter.
- rbanffy 5y agoInteresting. Thanks for the correction. So, the further you go towards the rim, the less the galactic year changes for you?
- matt_kantor 5y agoThere's some variability across different galaxies, but generally the curve is pretty flat if you're not right near the center. So the galactic year for a star at the outermost edge of our galaxy should be about the same as ours.
- ncmncm 5y agoStars are not, as a rule, orbiting in perfect circles. So, they are continually whizzing past one another as they trace out their respective orbits. The orbits are not even nice ellipses. Those only happen with point or (equivalently) spherical masses. The Milky Way is a quite irregular shape, and we are orbiting inside it. Our path bobs up and down through the galactic plane as we orbit, and not just once per orbit like a planet, but over and over. The planets like the sun that formed from the same gas cloud are long gone, stirred into the galactic soup.
- ncmncm 5y agos/planets/stars/