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We only have precise measurements of the magnetic field for one star i.e. the Sun. It turns out the Sun's magnetic field flips every eleven years i.e. the North and South poles switch over. This means there is no connection between the Sun's magnetic North and the orbits of the planets. Since we have no reason to suppose the Sun is special this means it is ...


3

In the "microscopic" sense, the formation of the Sun and solar system do not depend strongly on dark matter. Looking at things on the scale of GMCs, you can get a Jeans-unstable situation that will lead to star formation without invoking dark matter. There's a step much earlier in the history of the Universe that needs dark matter, though. In the early ...


5

Good answer from Kyle. I will just add that there is a great deal of effort going into trying to discover "solar twins". These are stars with such similar parameters (including age inferred from the HR diagram or asteroseismology, which can be good to about 10% in the best cases) and photospheric compositions to the Sun, that it is thought likely they must ...


16

You're right that the Sun being 4.5 billion years old makes observations difficult. The Sun goes around the Galaxy about once every 225 million years, so since the Sun formed it has gone around the Galaxy perhaps 20 times. The trouble is that the Galaxy is not like the Solar System: stars don't go around on nice nearly circular orbits, everything is a bit ...


1

NASA's JPL website has a fully referenced table that includes equatorial gravity (i.e. surface gravity at the equator). It looks like, for that table, they get the surface gravity by deriving it using a mass and radius rather than measuring it directly. However the citation for the mass of Venus is an article entitled Venus Gravity: 180th degree and order ...



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