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Stars that are rich in metals tend to be younger stars, and they tend to be richer in all of the elements above Helium. Moreover, you should note that any star is still mostly Hydrogen and Helium. Any other elements are much much less abundant. When looking at stars, we can see the elements that are in their atmosphere from the spectrum. The star Mu Leonis ...


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Technically yes, but no. Since the Wikipedia article regarding S2 notes an orbital period of 16.0518 years, with an eccentricity of 0.88466. A typical B0V star has a mass of ~18 solar masses while Sgr A* has a mass of 4.1 million solar masses. Applying Kepler's third law to Sgr A* and S2: $$\sqrt[3]{\frac{(16.0518 \text{ yr})^2 \cdot G(4.1\cdot10^6 M_\odot+...


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That would be a bigger black hole. Black holes are indestructible but a big one can consume a smaller one. The collision between anything and a black hole results in a black hole plus some optional debris from whatever the other thing is, so the result of a collision between two black holes is simply a bigger black hole.


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Whenever you look up, if your northern sky is away from a city, locating Polaris will anchor you because it is the closest relatively bright star to the north celestial pole. It stays in the same place. Every night and every day it is where it is. No matter what time of year, Polaris will be the base point for locating other northern constellations.


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The core of the star is the seat of nuclear fusion, yes, but by the time this energy reaches the surface (a few hundred thousand years at least in the case of our Sun), it has time to dissipate (from a [comparatively] small core to a huge outer surface). What’s left at the photosphere (the apparent surface of the star) is not nuclear fusion anymore, but ...


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The declination ($\delta$) of the celestial pole is 90°. Therefore the angle $\alpha=90-\delta$ and 2 times that value would be $180-2\delta$. Two Alpha is not the declination. The zenith distance is the angle measured from the zenith. I have added that angle (to the upper culmination) in this diagram: The zenith distance at upper culmination would be $(90-\...


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It's "in principle" possible. For example if we had a black hole the size of a small mountain on Earth (this kind of black hole are possible in theory but cannot form from stellar collapse) then it'd be impossible to confine in a laboratory, and it would fall through the Earth to eventually settle at the Earth's core. We could then argue that the ...


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