6 ms·
Stars are formed when clouds of gas and dust collapse into themselves. Either the cloud is big and dense enough to collapse into a star, or it will remain as a
by mesebrec 3y ago
Stars are formed when clouds of gas and dust collapse into themselves.
Either the cloud is big and dense enough to collapse into a star, or it will remain as a cloud.
Our Jupiter was created when, during the collapse, other forces pulled part of the collapsing cloud away from the sun, into a stable orbit.
> Stars form when the dust and gas clouds in a nebula cool, progressively fragment and eventually collapse under their own gravity. The smallest stars are about 80 Jupiter masses, below which the core is not dense enough to fuse hydrogen, but smaller objects can coalesce through the same process, including dimly glowing brown dwarfs – sometimes called failed stars – and, below about 13 Jupiter masses, planetary-mass objects. But theoretical predications suggest that the lower boundary for an object forming through a star-like gravitational collapse is about three to seven Jupiter masses.
https://www.theguardian.com/science/2023/oct/02/jumbos-jupiter-mass-binary-objects-discovery-orion-nebula-new-astronomical-category https://www.theguardian.com/science/2023/oct/02/jumbos-jupit...
- mesebrec 3y agoDon't quote me on this but I think the limiting factor is that gravitational pull needs to be stronger than the expansion of the universe.
- danparsonson 3y agoThe expansion of the universe isn't really related to the formation of individual stars.
- mbrumlow 3y agoBut it sounded cool.
- danparsonson 3y agoThat it did
- jl6 3y ago> Either the cloud is big and dense enough to collapse into a star, or it will remain as a cloud. Why is this? Why can’t a small molecular cloud coalesce into small objects?
- pfdietz 3y agoI suspect it may not be able to cool quickly enough. When a cloud collapses the gravitational potential energy goes into heat, and that heat has to be radiated for the collapse to continue. If the gas is too cold or too low in density it may not (I am guessing) be able to do this fast enough before the cloud is either disrupted or accretes too much additional gas.
- mr_toad 3y ago“An interstellar cloud of gas will remain in hydrostatic equilibrium as long as the kinetic energy of the gas pressure is in balance with the potential energy of the internal gravitational force.“ https://en.wikipedia.org/wiki/Star_formation#Cloud_collapse https://en.wikipedia.org/wiki/Star_formation#Cloud_collapse
- deleted 3y ago[deleted]
- piker 3y agoGas clouds are made of light molecules that a plant would need a large mass to retain, perhaps. Consider how Earth's gravity isn't strong enough to retain He.
- deleted 3y ago[deleted]
- Chris2048 3y ago> Earth's gravity isn't strong enough to retain He. Escape velocity is dependant on temperature, so Earth gravity can't retain He at Earths temperature - A colder Earth perhaps could.
- standardly 3y ago