How stars form slide show File
... •The bigger the initial protostar the quicker it gets hotter. •Massive protostars evolve to be normal (main sequence) stars very quickly (10,000 years); less massive stars evolve more slowly, up to 10 million years. •Eventually the core of the protostar becomes hot enough for nuclear fusion to take ...
... •The bigger the initial protostar the quicker it gets hotter. •Massive protostars evolve to be normal (main sequence) stars very quickly (10,000 years); less massive stars evolve more slowly, up to 10 million years. •Eventually the core of the protostar becomes hot enough for nuclear fusion to take ...
review
... • A sequence of thermonuclear fusion processes inside massive stars can continue to transform the nuclei of elements such as carbon, oxygen, etc. into heavier nuclei AND also generate excess energy, up to a limit beyond which no further energy-producing reactions can occur. The element that is produ ...
... • A sequence of thermonuclear fusion processes inside massive stars can continue to transform the nuclei of elements such as carbon, oxygen, etc. into heavier nuclei AND also generate excess energy, up to a limit beyond which no further energy-producing reactions can occur. The element that is produ ...
Nebulas & Stars
... their core They can live billions and even trillions of years, consuming their hydrogen fuel But ancient peoples had no idea what they were stars played a part in most religious ceremonies, and ...
... their core They can live billions and even trillions of years, consuming their hydrogen fuel But ancient peoples had no idea what they were stars played a part in most religious ceremonies, and ...
Document
... Start with a chemically homogeneous star of one solar mass Initial fractional Helium content by weight Y0 = 0.25 (shortly after ...
... Start with a chemically homogeneous star of one solar mass Initial fractional Helium content by weight Y0 = 0.25 (shortly after ...
Stellar Evolution
... stars fuse H into He in their cores - this is the defining characteristic of a main sequence star. ...
... stars fuse H into He in their cores - this is the defining characteristic of a main sequence star. ...
The Sun: Example of Radiation Laws
... High-mass stars (M > 8M⊙ ) evolve into both red and blue giants and supergiants as their cores burn heavier and heavier elements. ...
... High-mass stars (M > 8M⊙ ) evolve into both red and blue giants and supergiants as their cores burn heavier and heavier elements. ...
Chapter 25 Beyond Our Solar System
... When the core of a protostar has reached about 10 million K, pressure within is so great that nuclear fusion of hydrogen begins, and a star is born. • At some point after fusion begins, a star becomes a balanced, mainsequence star. For an average star, this stage lasts 90 percent of the star’s life. ...
... When the core of a protostar has reached about 10 million K, pressure within is so great that nuclear fusion of hydrogen begins, and a star is born. • At some point after fusion begins, a star becomes a balanced, mainsequence star. For an average star, this stage lasts 90 percent of the star’s life. ...
STARS
... • These are stars thirty times bigger than our Sun. • Small, very dense object with an extremely strong gravitational pull. • Nothing can escape from it; not even light. ...
... • These are stars thirty times bigger than our Sun. • Small, very dense object with an extremely strong gravitational pull. • Nothing can escape from it; not even light. ...
ASTRONOMY 1001 FALL SEMESTER 2004
... Star formation, gravitational contraction, protostar, pre-Main Sequence stars, hydrostatic equilibrium, Energy sources, fusion, proton-proton chain, CNO cycle, role of mass, role of gravity Evolution of solar type stars, main sequence turnoff, evolutionary tracks, shell burning, red giant phase, pla ...
... Star formation, gravitational contraction, protostar, pre-Main Sequence stars, hydrostatic equilibrium, Energy sources, fusion, proton-proton chain, CNO cycle, role of mass, role of gravity Evolution of solar type stars, main sequence turnoff, evolutionary tracks, shell burning, red giant phase, pla ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
... If stellar mass objects greater than 50 M do survive gravitational instabilities during birth, these objects would collapse very rapidly from protostar state and burn their thermonuclear fuel so quickly (i.e., within 10 million years) that few of these objects would be seen. When these hypermassive ...
... If stellar mass objects greater than 50 M do survive gravitational instabilities during birth, these objects would collapse very rapidly from protostar state and burn their thermonuclear fuel so quickly (i.e., within 10 million years) that few of these objects would be seen. When these hypermassive ...
Astronomy 103 – Midterm 2 – October 29, 2014
... 1 Contraction of the core and fusion of hydrogen to helium in a shell 2 Fusion of helium to carbon in the core 3 Contraction of the entire star 4 Fusion of hydrogen to helium in the core A The energy source for a star just after the helium flash. B The energy source of a star in its first red-giant ...
... 1 Contraction of the core and fusion of hydrogen to helium in a shell 2 Fusion of helium to carbon in the core 3 Contraction of the entire star 4 Fusion of hydrogen to helium in the core A The energy source for a star just after the helium flash. B The energy source of a star in its first red-giant ...
jackie822 beanerbutt777 life cycle of a star
... http://library.thinkquest.org/3103/nonshocked/topics/blackdwarfs/images/blackdwarfimg.gif ...
... http://library.thinkquest.org/3103/nonshocked/topics/blackdwarfs/images/blackdwarfimg.gif ...
here - Boise State University
... 14. What is the cycle or phase a star will spend most of its life in? 15. If our sun is currently 5 billion years old, how much longer will the sun shine brightly for before it runs out of fuel to burn? 16. After our Sun runs our of Hydrogen fuel, what kind of star will it become? 17. What is the na ...
... 14. What is the cycle or phase a star will spend most of its life in? 15. If our sun is currently 5 billion years old, how much longer will the sun shine brightly for before it runs out of fuel to burn? 16. After our Sun runs our of Hydrogen fuel, what kind of star will it become? 17. What is the na ...
Pistol Star of the Pistol Nebula
... around the Sun, it radiates as much as more than 10 million times more light than Sol (L= 10^6.3) and appears to have more than 150 Solar-masses, having been resolved as a single star down to a projected separation of 110 AUs (Figer et al, 1998). Indeed, the star may have started with as much as 200 ...
... around the Sun, it radiates as much as more than 10 million times more light than Sol (L= 10^6.3) and appears to have more than 150 Solar-masses, having been resolved as a single star down to a projected separation of 110 AUs (Figer et al, 1998). Indeed, the star may have started with as much as 200 ...
Stars
... causing the nebula to shrink. • A contracting cloud of gas and dust with enough mass to form a star is called a protostar. (Proto means “earliest” in Greek). • A star is born when the gas and dust become so dense and hot that nuclear fusion begins. ...
... causing the nebula to shrink. • A contracting cloud of gas and dust with enough mass to form a star is called a protostar. (Proto means “earliest” in Greek). • A star is born when the gas and dust become so dense and hot that nuclear fusion begins. ...
Starlight and What it Tells Us
... Why Black-Body Radiation is so Important • Color is directly related to temperature • Temperature is the only determinant of color • Energy per unit area is the same if temperature is the same – If two stars have the same color and distance, difference in brightness is due to difference in size – ...
... Why Black-Body Radiation is so Important • Color is directly related to temperature • Temperature is the only determinant of color • Energy per unit area is the same if temperature is the same – If two stars have the same color and distance, difference in brightness is due to difference in size – ...
STARS
... giants are HUGE. They’re not all the same size as each other, but they are all big. *The little white dot is how big our sun is right now, compared to the red giant Antares, the biggest one shown in the picture at left. ...
... giants are HUGE. They’re not all the same size as each other, but they are all big. *The little white dot is how big our sun is right now, compared to the red giant Antares, the biggest one shown in the picture at left. ...
Properties of Stars
... measure how large the star is, what temperature it is, and what its apparent brightness would be at 32.5 light-years ...
... measure how large the star is, what temperature it is, and what its apparent brightness would be at 32.5 light-years ...
Evolution of Stars and Galaxies
... After core uses up He, contracts more Outer layer escapes into space Leaves behind a hot, dense core (about the size of Earth) Eventually will cool and stop giving off light ...
... After core uses up He, contracts more Outer layer escapes into space Leaves behind a hot, dense core (about the size of Earth) Eventually will cool and stop giving off light ...
Page 1 Astronomy 110 Homework #08 Assigned: 03/13/2007 Due
... A) to dim and redden distant stars by preferentially scattering their blue light. B) to scatter the red light from stars preferentially, making them appear more blue than expected. C) almost nonexistent, because light does not interact with dust. D) to make stars appear less bright than expected by ...
... A) to dim and redden distant stars by preferentially scattering their blue light. B) to scatter the red light from stars preferentially, making them appear more blue than expected. C) almost nonexistent, because light does not interact with dust. D) to make stars appear less bright than expected by ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.