Physical properties

Hi! You are thinking now stars are so beautiful and why? Oh! This is very convenient! But what materials are used? It`s realm of cosmology and I`ll show you them.

The color of stars is determined by the temperature and the color becomes blue, light blue, white, sour orange, yellow, sour orange, and red. It`s categorized ( Anie. J. Canon. 1863~1941) as O, B, A, G, K, M, R, N, S types in order. ( a famous phrase to remember the order ”Oh, Be A Fine Girl, Kiss Me Right Now, Sweet”) It`s originally categorized in order “A, B, C, ・・・” by its identity but finally divided 10 rooms and arranged in order of higher temperature, thus it`s in this order. Which color did you think the most high temperature? Maybe red? As you know as long as this blog, it`s blue. The colors are determined different reason in planets and fixed star. On planets, they reflect light from fixed star and the color is its surface. The Earth has atmosphere on the surface and it reflects blue so the Earth is blue. However, fixed stars get off light. If you heats wire, it will get off the red light at first and gradually the color changes to white then blue. ( this step of its temperature is over 10000K!) the light is called spectrum. The fixed stars do nuclear reaction and the atoms become heavier one, as the hydrogen to helium to ・・to iron. Iron is the most steady atom chemically. A bigger and heaver one has higher energy and higher temperature so it`s bright and the color is tend to be blue. In contrast, a smaller and lower one do less nuclear reaction so it has hydrogen in the most high ratio and become a “red giant”, which is filled with mostly gas, low energy, but is gigantic so is seen as a red star.

A interesting story, why a high mass star has so high energy? It relate to science. The higher mass a star has, the heaver gravity it has. The nuclear reaction occur when the one nucleus close enough to the other one. Usually they resist each other electric power. An organization of atom is the protons are inner and electrons are outer so if you make two of them close, they react strong power and you have to add very high energy. However, a gravity of gigantic mass made it possible. When the nucleus close enough, nuclear force, a so strong but takes so short range that of minus 15^th powers of 10m, is taken.( I`ll explain the details of these power next week, wait a minutes) therefore, the high mass causes the more intensely nuclear reaction, get off the higher energy. BUT, it`s not anyways good to have high mass. The nuclear reaction takes fuel, the more intensely nuclear reaction occur, the more early fuels are taken away. A living time of star, the 10 times of mass of sun is said about 2,600 million years but sun is said 10 billion years.

Just like a living way of human! I`ll live bright but long! see you next week:)