Death and birth of stars Assignment Example | Topics and Well Written Essays - 250 words

Death and birth of stars - Assignment Example The last known supernova occurred about 140 years ago in our galaxy. It was not recognized because it occurred close to the galaxy center. Our galaxy has been deficient in production of supernovas because only one has occurred in about 140 years as opposed to the documented probabilities. 4. One solar mass pre-main sequence tends to radiate more energy in the conformation of excessive heat: the need to acquire stability. Less energy is radiated upon entry into main sequence. It reaches equilibrium and becomes opaque. Energy tends to be conserved internally and hence less energy radiated and thus the observed reduction in luminosity. 5. Collision and Fusion force theory: it is proposed that water came to be on earth as a result of bombardment of comets; ‘wet’ asteroids and ice particles. Even though it may seem right, a humongous number of comets would be required to collide and form the huge should have been 6.36 million with a 40% ice-water as mass. This theory could be misleading because such huge number of comets might not have existed to pass close to earth, collide and form water. It is not clear if they could have produced about 1.33x10^18 tons of all water on earth. Second is the adhesion of water on interstellar dust particles theory. One theory proposed by Dr. Drake has indicated that water was already present on dust particles from the interstellar clouds. This through computer stimulations has established strong evidence that through adhesion forces; it could just be as true that water came to be on earth under such conditions. These forces were responsible for retention of water on dust particles even under extreme temperatures and pressure. This later joined to form water. This theory poses certain inconsistencies because it’s hard to really very water could have been held for that long on interstellar dust when planets