Life Cycle of a Star

1. http://en.wikipedia.org/wiki/Nebula By: Sierra-Rae Morgan And Alex Goff The Life Cycle of a Star Life Cycle of a Star By: Sierra-Rae Morgan and Alex Goff http://www.astro.keele.ac.uk/workx/starlife/StarpageS_26M.html

2. What is a star? *Stars are big hot bodies of glowing gas, which start there lives as nebulae. *They vary in temperature, mass and size. *The color of a star determines the temperature of a star. *Red is the coolest star Blue is the hottest

3. Nebula *a nebula is an interstellar cloud of dust, helium gas, plasma, and hydrogen gas. *was originally a general name for any astronomical object including galaxies including the milky way. *they often form star forming regions, like the eagle nebula. *this nebula is one of NASA’s most famous images. *they form when a gravitational collapse of gas in the interstellar medium. http://www.godandscience.org/love/nebula.html

4. Planetary Nebula *An emission nebula made of a glowing shell of gas and plasma formed by certain types of stars when they die. *They are a relatively short phenomenon. *The name originated in the 18th century because they looked similar to giant planets. *They are an important objects in astronomy because they play an important role in chemical evolution of the galaxy. http://www.noao.edu/jacoby/ngc_650-1.html

5. Proto-star *Is a large object that forms by contraction out of the gas of a giant molecular cloud in the gas and dust that pervade interstellar space. *The protostellar phase is an early stage in the process of star formation. *The term proto-star appears to have been first used in print in 1889. *It may last from 100,000 to 10 million years, depending on the mass of the star. It may last from 100,000 to 10 million years, depending on the mass of the star. http://aspire.cosmic-ray.org/labs/star_life/starlife_proto.html

6. Brown Dwarf *Brown dwarfs is a term made Jill Tarter in 1975. *Brown dwarfs were originally called black dwarfs, which was a classification for a dark subs teller objects floating freely which were to low in mass to have stable hydrogen fusion. *For many years brown dwarfs were frustrating and seemed useless , however in 1988, at the university of California, professors Eric Becklin and Ben Zuckerman found a faint companion to GD165 in an inferred of search of white dwarfs. http://astro.berkeley.edu/~basri/bdwarfs/index.html

7. Hydrogen Fusion * In hydrogen fusion four hydrogen nuclei come together to make a helium nucleus. *The main important thing to remember is that this cycle releases energy in the core of the star. *This generates energy of our sun. *This whole process happens in three steps. • http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Nuclear_Reactions/Fusion/Fusion_in_stars/H_fusion.html

8. Helium Fusion *Helium fusion is a kind of nuclear fusion. *It is rare on earth and is looked for in the use of nuclear fusion research. *If the central temperature of a star exceeds 100 million Kelvins, as may happen in the later phase of red giants and red super giants, then helium can fuse to form beryllium and then carbon.

9. Main Sequence Star *they are characterized by their source of energy, they are all undergoing fusion hydrogen into helium within their cores. *the amount of fuel available for the star to use depends on its mass. *mass is a huge factor which determines the life span of a life star. *stars on the main sequence are unchanging for long periods of time. These stars must be accountable of stability. • http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_mainsequence.html

10. Red Giant *A luminous giant star phase of stellar evolution. *The outer atmosphere f low or intermediate mass that is an a late is inflated , making the radius big and the surface temperature low. *The appearance of a Red Giant is from yellow-orange to red. *The most common red giants are so called red giant branch stars. *Who’s shells are still fusing hydrogen and helium while the core has inactive helium. http://www.historyoftheuniverse.com/starold.html

11. Super-Giant *Are among the most massive stars. *Their radius is usually from 30-500 but it can stretch to 1,000 solar radii. *They can have masses from 10-70 solar masses. *The most luminous supergiant are often classified as hyper-giants. *Their brightness can stretch up to 30,000 up to hundreds and thousands of their solar luminosity. *Super-giants radiate less energy of unit per area then those of blue super giants.which means if red super giants give off more luminosity red super giants are larger then blue super giants. http://hubblesite.org/gallery/album/entire/pr2005002f/

12. White Dwarf *A White Dwarf is also called a Degenerate Dwarf. *A white dwarf is composed of an electron degenerate matter, which is characterized by atoms stripped of their electrons. Which makes it very dense. *A white dwarfs mass is comparable to the sun, and its volume is compared to the earth. http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html

13. Black Dwarfs *A black dwarf is a white dwarf or neutron star that has cooled off significantly and no longer gives off much heat or light. *In billions and billions of years no black dwarfs are expected to exist in the universe. *Black dwarfs are difficult to detect because they admit very little radiation, a theory is people might be able to detect black dwarfs by its gravitational influence. http://www.daviddarling.info/encyclopedia/B/blackdwarf.html

14. Black Hole *Is a region of space in which gravitational field is so powerful that nothing, not even light , can escape. *The black hole has a one way surface, objects can go in to it, but can not come back out. *It is called a black hole because it absorbs all the light that hits it , reflecting nothing. http://en.wikipedia.org/wiki/Black_hole

15. Neutron Star *Is a type of remnant that can result from the gravitational collapse of a humongous star. *These stars are made almost entirely out of neutrons. *The are extremely hot and are supported against further collapse, by the Pauli exclusion principle, this principle states that no two neutrons can occupy the same space simultaneously. *A neutron star has a mass between 1.35 and 2.1 solar masses http://en.wikipedia.org/wiki/Neutron_star

16. Supernova *Is a stellar explosion. This means it is a big explosion of a star. *During this short interval, a supernova can radiate as much energy as the Sun could emit over its life span. *The explosion expels much or all of a star's material at a velocity of up to 30,000 km/s, that’s a tenth the speed of light, driving a shock wave into the surrounding interstellar medium. *Several kinds of supernovae exist that may be triggered in one of two ways, either turning off or suddenly turning on the production of energy through nuclear fusion. http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernovae.html

17. Citations *http://www.astro.keele.ac.uk/workx/starlife/StarpageS_26M.html *http://en.wikipedia.org/wiki/Black_dwarf *http://en.wikipedia.org/wiki/Black_hole *http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_mainsequence.html *http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Nuclear_Reactions/Fusion/Fusion_in_stars/H_fusion.html *http://en.wikipedia.org/wiki/Protostar *http://www.daviddarling.info/encyclopedia/P/protostar.html *