Tag Info

Hot answers tagged

11

If the sun was principally composed of Iron, then this would be apparent in the spectrum of light from the sun (which is how we know what stars are made of) (but see comment by @Keith Thompson below, the spectra only tells you about the surface, rather than the core). The fact that all solar physicists bar one seem to think it is made up of hydrogen and ...


9

According to the Case Western Reserve University webpage The Edge of the Solar System (2006) an important consideration is that The whole concept of an "edge" is somewhat inaccurate as far as the solar system is concerned, for there is no physical boundary to it - there is no wall past which there's a sign that says, "Solar System Ends Here." There are, ...


6

Here's my answer. I'll try to make it as comprehensive as possible. It's pretty hard to define the edge of the solar system. Most people would probably define it as where objects are no longer gravitationally bound to the Sun. That just shifts the question a little, though: Where is that dividing line? To try to answer this, I'll go over the regions of the ...


6

Over the year, the sun follows a path known as an annalemma. This is a figure eight shape and is caused by the combination of the Earth's rotation around the Sun and its tilt relative to the plane of the equator. The analemma can be observed by pointing a camera at the sun, and at the same time each month, take a picture and over lay the images: Taking a ...


3

The classification of stars using spectral class is a very useful classification when considering the properties of (the atmosphere of) a star at that moment. If you consider the different stages in human development (embryo, fetus, infant, toddler, etc...), for instance, here one person also continuously changes its class. So it is not ...


2

Here are the results of some arbitrary cutoffs for the "core" based on $2010$ solar models calculated by Guenther et al: Contributing $99\%$ of the total luminosity:$R = 25.5\%$, $M = 9.88\times10^{29}\,\mathrm{kg}$ ($49.7\%$). Nuclear reaction rate falls below $1\%$ of central rate:$R= 27.2\%$, $M = 1.07\times10^{30}\,\mathrm{kg}$ ($54.0\%$). Overall, ...


2

I'm getting a slightly different figure from space.com (not my favorite source, but a source nonetheless), which says The core extends from the sun's center to about a quarter of the way to its surface. Although it only makes up roughly 2 percent of the sun's volume, it is almost 15 times the density of lead and holds nearly half of the sun's mass. I ...


2

Even if the answer has already been accepted, more evidences can contribute to this thought-provoking topic. I think, as it has been mentioned, eliosismology is a good way to map the interior of the star, but I am not able to argue about it. Another disproof, comes from neutrinos. Interior of Sun can be investigated by neutrinos detection, which do not ...


1

First of all, your first question. This source clearly state that Values are given in the usual logarithmic (dex) scale, for the same formula that you quoted (similar job). It is a bit tricky as the article "explains" the values, but you have to pay attention to the exact definition. I think it is better to work out with an example. Let's take the He. ...


1

I think Mr. Marsupial's answer should get a star, but to put some of this in layman's terms, here's my answer. The process of fusing iron into other elements, whether within a star or within a laboratory pulls more energy from the reaction than it creates. It is the first element in star evolution that does this, and is therefore associated closely with ...


1

We wouldn't feel the ejection of another planet off the solar system, since the attractive force of distant planets to Earth is very low. Only close encounters of Earth with other planets would cause noticeable up to severe changes on Earth. This would be caused mainly by tidal forces due to different acceleration for different parts of Earth, or by ...


1

The further north you go, the time between sunset and darkness becomes longer, no matter the season. The reason is due to the velocity at that latitude. If there is 10 min of twilight on the equator, then there is $10\sqrt{2}$ min at 45° latitude, 20 min at 60° latitude, ... Added: I used the website that @barrycarter listed above and discovered that there ...



Only top voted, non community-wiki answers of a minimum length are eligible