Tag Info

New answers tagged

1

In the early days of the solar system, it is generally believed , as the comment above implies, that it was a place of constant collisions. The moon may have been part of the Earth, there is strong evidence for that, and an impact is the most probable way that it would be have been able to became a separate orbiting body. For the giant planets, Jupiter ...


5

The image is that of the entire sky above the telescope taken with some kind of fish-eye lens. It is quite common at observatories to use such arrangements to monitor for cloud cover. However you seem to have found a particularly poor example - possibly using a CCD imager with very few pixels. It is also possible that there is some light cirrus over the ...


1

As you might know, we use RA (Right Ascension) and DEC(declination) to locate the stars in the sky. Now the RA and DEC co-rodinates of any star is fixed. However, locally to locate a star we use ALT / AZ co-ordinate system. The ALT and AZ of a star depends upon the LAT/LONG of the place you are observing from and the time. There are many online converters ...


1

The answer is a qualified yes, depending on your definition of fusion. If you collect together a mass of iron less than about $1.2M_{\odot}$ it is possible for that to form a stable configuration, a little smaller than the size of the Earth, supported by electron degeneracy pressure. Such a star would just sit there and cool forever and all that would ...


0

Iron won't fuse into heavier elements. It's a question of nuclear physics. Iron is the most stable form of nuclear matter. In other words, iron has the lowest energy configuration of all nuclear matter. Fusion can appear in the cores of stars because it's an exothermic process, that is, fusing nuclei lighter than iron can lower the nuclear matter's energy ...


0

Let's say a field of stars all die within a short amount of time. Just for argument's sake they produce a debris field of iron ( or any other heavy element). Provided that there is enough time the debris will agglomerate, we know this. My question: Given enough mass, will this agglomeration of heavy elements fuse into even heavier elements? ...


1

As I understand it regular fusion in a star takes light elements as input and the output is heavier elements and energy. There are several potential steps in the regular process, e.g: Hydrogen fusing to helium and producing energy which keeps the star from collapsing. After a lot of hydrygen is spent and helium has collected in the center of the star the ...


0

As I understand it, iron will not be able to fuse with iron no matter how much of it you have gravitationally bound. Instead to fuse iron atoms together requires a supernova.


3

Rigid bodies with three distinct moments of inertia have two stable rotation axes, the axes with the greatest and least moments of inertia (typically the shortest and longest axes). Non-rigid bodies have but one stable rotation axis, the axis with the greatest moment of inertia. The axis with the least moment of inertia becomes unstable thanks to entropy. ...


3

the flux drops off as the square of the distance, but the solid angle subtended by the source drops off the same way, so surface brightness is constant, right? Right. But what happens when you can no longer resolve the source? Then the "solid angle subtended by the source" stops dropping, and only the reduced flux of the entire source can be ...


3

The Lagrange points are only well defined for a two body system. The Earth-Sun Lagrange points exist only because the perturbations caused by the Moon and the other planets are relatively small. By contrast there are lots and lots of stars and dark matter between the Earth and Sgr A*, so this isn't even remotely a two body system. The mass of Sgr A* is ...



Top 50 recent answers are included