CHAPTER 7—ATOMS AND STARLIGHT
... The _______________ of a gas is a measure of the average speed of the particles in the gas. a. heat b. composition c. temperature d. blue shift e. binding energy The two most abundant elements in the sun are a. nitrogen and oxygen. b. hydrogen and helium. c. sulfur and iron. d. carbon and hydrogen. ...
... The _______________ of a gas is a measure of the average speed of the particles in the gas. a. heat b. composition c. temperature d. blue shift e. binding energy The two most abundant elements in the sun are a. nitrogen and oxygen. b. hydrogen and helium. c. sulfur and iron. d. carbon and hydrogen. ...
1. setting the scene 2. the cosmic dark ages and the first stars
... alternative method to investigate the composition of the gas ejected by the explosions of the First Stars. If the oldest stars in the halo of our Galaxy really formed from such gas, should it not be possible – by looking at very distant galaxies – to detect the gas before it was incorporated into a ...
... alternative method to investigate the composition of the gas ejected by the explosions of the First Stars. If the oldest stars in the halo of our Galaxy really formed from such gas, should it not be possible – by looking at very distant galaxies – to detect the gas before it was incorporated into a ...
Lives of the Stars Lecture 3: What makes a star?
... Now, there are four simple laws which must be satisfied: • Conservation of mass: total mass equals the sum of shell masses • Conservation of energy: total luminosity equals the sum of energy generated in each shell • Hydrostatic equilibrium: the outward pressure in each shell balances the inward gr ...
... Now, there are four simple laws which must be satisfied: • Conservation of mass: total mass equals the sum of shell masses • Conservation of energy: total luminosity equals the sum of energy generated in each shell • Hydrostatic equilibrium: the outward pressure in each shell balances the inward gr ...
Virtual Sky II (Rev 10/11)
... Procedure 4 Arcturus Nears the Sun Over long periods the appearance of constellations will change. Go to ‘Open Settings’ to open up Settings> Arcturus Nears Sun. Initiate the demo by clicking start. Stop when Arcturus reaches the boundary (purple line) between Bootes and Virgo. How many years did it ...
... Procedure 4 Arcturus Nears the Sun Over long periods the appearance of constellations will change. Go to ‘Open Settings’ to open up Settings> Arcturus Nears Sun. Initiate the demo by clicking start. Stop when Arcturus reaches the boundary (purple line) between Bootes and Virgo. How many years did it ...
The Teleological Argument - University of Colorado Boulder
... 20. ground state energy level for 4He if larger: universe would contain insufficient carbon and oxygen for life if smaller: same as above 21. decay rate of 8Be if slower: heavy element fusion would generate catastrophic explosions in all the stars if faster: no element heavier than beryllium would f ...
... 20. ground state energy level for 4He if larger: universe would contain insufficient carbon and oxygen for life if smaller: same as above 21. decay rate of 8Be if slower: heavy element fusion would generate catastrophic explosions in all the stars if faster: no element heavier than beryllium would f ...
Toys Watch the Sky - The Sun is a close star
... The Sun is a huge ball of glowing gases (mostly hydrogen and helium). It is the star at the centre of our Solar System. The Sun is located in an outer spiral arm of the Milky Way Galaxy, approximately 28,000 light-years from the galaxy's centre. (One light year is about 10 million million km.) In co ...
... The Sun is a huge ball of glowing gases (mostly hydrogen and helium). It is the star at the centre of our Solar System. The Sun is located in an outer spiral arm of the Milky Way Galaxy, approximately 28,000 light-years from the galaxy's centre. (One light year is about 10 million million km.) In co ...
The Parent Stars of New Extrasolar Planet System Candidates
... Not only did the stellar evolution model derive ages for the selected stars, but it also aided in refining initial estimates of their hydrogen, helium, and metal abundances. For Gliese 614 in particular, results were quite different than expected. In addition to a high luminosity, the star appears to ...
... Not only did the stellar evolution model derive ages for the selected stars, but it also aided in refining initial estimates of their hydrogen, helium, and metal abundances. For Gliese 614 in particular, results were quite different than expected. In addition to a high luminosity, the star appears to ...
Astronomy 15 - Problem Set Number 4 1) Suppose one were to
... properties of a CCD signal are somewhat similar to those from a photomultiplier, but there are several complicating factors, so a photomultiplier makes a simpler example. Question: Suppose a star delivers about 1000 pulses per second in a photomultiplier attached to a telescope. Assume for now that ...
... properties of a CCD signal are somewhat similar to those from a photomultiplier, but there are several complicating factors, so a photomultiplier makes a simpler example. Question: Suppose a star delivers about 1000 pulses per second in a photomultiplier attached to a telescope. Assume for now that ...
Burgess_final - University of Hertfordshire
... 348. Their atmospheres all show evidence of methane absorption which was used to select and identify these young objects. "There has been some controversy about identifying young, low mass brown dwarfs in this region. An object of a similar mass was discovered in 2002, but some groups have argued t ...
... 348. Their atmospheres all show evidence of methane absorption which was used to select and identify these young objects. "There has been some controversy about identifying young, low mass brown dwarfs in this region. An object of a similar mass was discovered in 2002, but some groups have argued t ...
The 100-billion-body problem A full-scale computer simulation of the
... The stars left behind give up some of their kinetic energy in this transaction, but the cluster as a whole also loses mass, so that the stars are less tightly bound together. The ultimate fate of the cluster may be the very opposite of condensation: evaporation, as all of the stars disperse. The Mil ...
... The stars left behind give up some of their kinetic energy in this transaction, but the cluster as a whole also loses mass, so that the stars are less tightly bound together. The ultimate fate of the cluster may be the very opposite of condensation: evaporation, as all of the stars disperse. The Mil ...
Night Sky Course Stars and Star Clusters within the
... about 15 light years. The cluster is only about 500 light years away – farther than the Pleiades. The bright orange stars are the ones that have had time to evolve into red giants. (Given the estimates of mass for those stars still remaining on the main sequence, we can use our models of stellar evo ...
... about 15 light years. The cluster is only about 500 light years away – farther than the Pleiades. The bright orange stars are the ones that have had time to evolve into red giants. (Given the estimates of mass for those stars still remaining on the main sequence, we can use our models of stellar evo ...
The Distribution of Stars Most Likely to Harbor Intelligent Life
... results with the distribution of main sequence stellar masses to obtain the distribution of stars most likely to possess habitable planets as a function of stellar lifetime. We then impose the self selection condition that an intelligent observer can only find themselves around a star with a lifetim ...
... results with the distribution of main sequence stellar masses to obtain the distribution of stars most likely to possess habitable planets as a function of stellar lifetime. We then impose the self selection condition that an intelligent observer can only find themselves around a star with a lifetim ...
What is Epsilon Aurigae?
... The Eclipsed Star: • F spectral type, temperature 7800 K • Very large (radius ~150 Rsun) • Is it a massive supergiant (20 Msun)? Supernova in the future? • Or a low mass star (up to a few Msun)? post-Asymptotic Giant Branch object? = Dying star, planetary nebula in the next few thousand years ...
... The Eclipsed Star: • F spectral type, temperature 7800 K • Very large (radius ~150 Rsun) • Is it a massive supergiant (20 Msun)? Supernova in the future? • Or a low mass star (up to a few Msun)? post-Asymptotic Giant Branch object? = Dying star, planetary nebula in the next few thousand years ...
ASTR 1101-001 Spring 2008 - Louisiana State University
... More About: Continuous Spectra from Hot Dense Gases (or Solids) • Kirchhoff’s 1st Law: Hot dense gas produces a continuous spectrum (a complete rainbow of colors) • A plot of light intensity versus wavelength always has the same general appearance (blackbody function): – Very little light at very s ...
... More About: Continuous Spectra from Hot Dense Gases (or Solids) • Kirchhoff’s 1st Law: Hot dense gas produces a continuous spectrum (a complete rainbow of colors) • A plot of light intensity versus wavelength always has the same general appearance (blackbody function): – Very little light at very s ...
A historical perspective on the discovery of neutron stars
... Nuclear forces and maximum mass of neutron stars In 1959, Cameron constructed neutron-star models using the Skyrme equation of state for high-density matter. He found that: nuclear forces considerably stiffen the EoS the maximum mass of neutron stars Mmax ≃ 2M⊙ is much higher than that found by Opp ...
... Nuclear forces and maximum mass of neutron stars In 1959, Cameron constructed neutron-star models using the Skyrme equation of state for high-density matter. He found that: nuclear forces considerably stiffen the EoS the maximum mass of neutron stars Mmax ≃ 2M⊙ is much higher than that found by Opp ...
PowerPoint
... a) Clouds fragment into smaller objects, forming many stars at one time. b) One star forms; other matter goes into planets, moons, asteroids, & comets. c) Clouds rotate & throw off mass until only enough is left to form one star. ...
... a) Clouds fragment into smaller objects, forming many stars at one time. b) One star forms; other matter goes into planets, moons, asteroids, & comets. c) Clouds rotate & throw off mass until only enough is left to form one star. ...
Lecture 9: Supernovae
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...
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.