Life Cycle of Stars

When stars died, chemicals other than hydrogen and helium formed, which led to the next level of complexity—Heavier Chemical Element. Most stars spent about 90% of their life over billions of years on during protons and hydrogen nuclei into helium nuclei. When they run out of fuel, the furnace at the center of the star stopped supporting the star, and gravity took over. Small stars did not have much pressure at the center. They burned hydrogen slowly over billions of years at relatively low temperatures. When they died, they would slowly fade away. However, great stars had so much mass that they can create enormous pressures and temperature, and when the giant stars ran out of hydrogen, the temperature got cranked up even higher, which led the star to collapse. The high temperature that the collapse caused was able to make helium nuclei fuse into nuclei of carbon. When a star used up its helium, it collapsed again, and the cycle started over. The star heated up and began to fuse carbon to form

Stars are the most recognized astronomical object in space and they represent the building blocks of galaxies. Stars distribute elements such as: carbon, nitrogen, and oxygen. A star develops from a cloud of hydrogen and helium, the dust clouds that are scattered throughout galaxies. An example of a dust cloud is the Orion Nebula. The gas and dust begin to collapse from its own gravitational pull. As the cloud collapses, the middle gets hotter. This is known as a prostar. A dense and hot core forms which begins to collect dust and gas. All this material may not end up as a part of the star but can become planets, asteroids, comets, or remain dust. A star about the size of our sun can up to 50 million years to mature. The smallest stars are

2) Why are there different brightness of stars and how do we describe their brightness as compared to one another?

5. On what kind of diagram are stars plotted according to their surface temperature and luminosity?

Many physical properties of stars can be found by using a little bit of light. One property of a star is luminosity. Luminosity is the quantity of energy created in a star and then released as electromagnetic radiation. The brightness of a star is a blend of luminosity and distance of a star and can also depend on the quantity of energy absorbed in the direction of a star. Another property of a star is distance. Astronomers use parallax to establish the distance to an object. As Earth travels around the Sun, they monitor neighboring stars from various positions. They are then able to measure how much the star seems to move to establish the distance to the star.

Cooler stars emit heat in the infrared area of the electromagnetic spectrum, and thus, they appear to be red. It should also be noted that hot stars radiate energy at the ultraviolet and blue areas, making them appear white or blue. The surface temperature of a celestial object can be determined by using the relationship between the wavelength of the light and the temperature of the blackbody and in the case of an increase in temperature, the tip of the spectrum becomes shorter in

They are very luminous stars that have a relatively cool surface temperature compared to the stars in the main sequence that have about the same luminosity. Red giants typically have low to intermediate mass than a regular star, even though they are about 1000 times larger in the red giant phase of stellar evolution. Red supergiants are known as the biggest stars by radius. The biggest red supergiant is mentioned as VY Canis Majoris. This star is about 1800 times bigger than our sun. Although there are plenty of red giants in space, none of them are that close to us. The closest red giant is Gamma Crucis (88 light years away).3

As the source moves so does the wavelength of it. As it moves away it will become red as the wavelengths change.

These clouds can exist undisturbed for extended periods, as they are quite able to withstand their own gravity, due to the low density and magnetic field that protects it from drifting into open space, and are considered to be stable. If a nearby, external

According to the book, "If you know a star’s temperature and luminosity, you can determine its radius" (Seeds 151). The luminosity of a star is related to its absolute magnitude, and its spectral class has a relation to the star's temperature. So, in order to estimate the size of Betelgeuse, we would need both its luminosity (in which we can substitute its absolute magnitude) and its temperature (spectral class), which we have been provided. The absolute magnitude refers to the brightness of a star "if it were 10 pc away" (Seeds 145), and the lower the number the brighter the star (and vice versa). According to the spectral sequence, which goes O, B, A, F, G, K, then M, "O stars are the hottest...M stars, the coolest" (Seeds 148), with M stars being orange/red in color.

For two stars of identical size and temperature, the closer one to us will appear brighter.

Also like cars, a much larger star burns more fuel than a smaller star. This difference in “fuel efficiency” forms the basis for how stars receive categorization. In the eco-friendly section of the star dealership, one may find the most humble of all celestial objects: The red dwarf. As the name implies, they usually only possess half the size of our sun or less. The red dwarf’s small size and lack of resources in its creation places it firmly as the most common star in the universe; though, their lack of size hides from the naked eye. Despite this shortcoming, red dwarfs possess one advantage over their larger and brighter counterparts: Life expectancy. Of course, these monstrous spheres of ignited hydrogen possess no life, but scientists consider them “alive” until they run out of fuel and burn out, and red dwarfs take a long time to burn out. In fact, in the Universe’s 13 billion year long existence, every red dwarf to ever form remains burning to this day. This longevity, combined with their abundance, makes a planet in a red dwarf star system the perfect candidate for the first interstellar colony; so despite their relatively quiet existence, these little guys potentially hold the future of humanity.

Stella nebula-The nebula part of the name actually means cloud,an its actually spelled like”nebulae” its a latin term and nebulae is a bunch of massive clouds or just a massive cloud filled with dust,hydrogen,helium gas and plasma.Stella nebula is located about 10,000 light years from earth. People say stella nurseries is where the stars was born.

Main sequence stars like our own sun enduring in a state of nuclear fusion during which they will produce energy for billions of years by replacing hydrogen to helium. Stars change over billions of years. When their main sequence phase ends they pass through other states of existence according to their size and other characteristics. The larger a star's mass, the shorter its lifespan is. As stars move toward the end of their lives, much of their hydrogen will be converted to helium. Helium sinks to the star's core and raises the star's temperature—causing its outer shell to expand. These large, puffy stars are known as Red Giants. The red giant phase is actually a prelude to a star shedding its outer layers and becoming a small, dense body called a White Dwarf. White dwarfs cool down for billions and billions of years, until they finally go dark and produce no energy at all. Once this happens, scientists have yet to observe, such stars become known as Black Dwarfs. A few stars avoid this evolutionary path and instead go out with a bang, exploding as Supernovae. These violent explosions leave behind a small core that will then turn into something called a Neutron Star or even, if the remainder is large enough, it is then turned into something called a Black Hole.

     There are four different types of stars: Protostars, Bright Stars, Red Giants, and White Dwarfs. Protostars are stars that are on the verge of being born. They are glowing clouds of dust and gas. Gravity pulls on every atom moving them towards the center of the cloud of dust, which causes the Protostar to collapse. Over a period of twenty million years the star begins to form and 10 million years after the pocket of gas was formed, a star is born.