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6

What's happening is that (i) the star is spinning and (ii) it is being eclipsed (by an exoplanet perhaps?) As the exoplanet (or whatever dark object eclipses the star, the same explanation would apply to a brown dwarf or very low-mass companion) traverses across the face of the star it will eclipse parts of the stellar surface that gave their own specific ...


3

Saying $g\propto \frac{M}{R}$ is the same as saying that there exists a constant $k$ for which $g = k\frac{M}{R}$. This constant $k$ is the same for every planet or moon. In these equations, you can replace $M$ and $R$ by the mass and ratio of the Earth to get the proportionality for the Earth. Then you can replace $M$ and $R$ with the mass and ratio of any ...


6

The first part is just replacing $M$ with $M_E$ and so forth. You get two statements of proportionality, one with the $E$ values and one with the $M$ values. The second part is algebraic division. Mathematically if $a\propto b$, and if $a_1,a_2,b_1,b_2$ are specific values that are in this proportion. $a_1=kb_1$ and $a_2=kb_2$ for some constant $k$. ...


1

You can differentiate between planet (Did you mean asteroid? Planets are quite bright.) and noise quite easily. Just take three pictures of the sky and they will be probably quite noisy. If some spot changes its position on all three pictures, then this is some near object (astronomically near). You can additionally verify it if its trajectory is line or not....


4

There are many extremely widespread misconceptions about cosmology. One is the idea that there's some importance to cosmological recession speeds larger than $c$. In reality, recessional speeds are defined in a somewhat peculiar way and the value $c$ has no significance in them. It's not a limiting speed, and it's not in any useful sense "the speed of ...


7

The age of the universe is not calculated based on the size of the visible universe. The age of the universe is being calculated based on the fact that the laws of nature have no direction. This means that you can use the laws of nature to predict future behavior, but also assume previous behavior. Based on calculating backwards with the laws of nature, for ...


1

Not being an expert in star formation, I found a well-written paper summary from which I conclude that typical star formation rates range between $6 \ldots 24 M_\odot / yr$. The blog quotes the following graph by M. Boquien, V. Buat, and V. Perret, see https://arxiv.org/abs/1409.5792 In this paper we investigate in isolation the impact of a variable star ...


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