Answer
... Luminosity remains constant at about 1 Lsun until about 10,000 Myr when it suddenly (and briefly) increases to over 4500 Lsun. 2. Describe how the radius of this star changes with time. Radius remains constant at about 1 Rsun until about 10,000 Myr when it suddenly (and briefly) increases to over 20 ...
... Luminosity remains constant at about 1 Lsun until about 10,000 Myr when it suddenly (and briefly) increases to over 4500 Lsun. 2. Describe how the radius of this star changes with time. Radius remains constant at about 1 Rsun until about 10,000 Myr when it suddenly (and briefly) increases to over 20 ...
at A-stars?
... brightness because they cannot achieve proper balance between power welling up from the core and power radiated from the surface • Most pulsating variable stars inhabit an instability strip on the H-R diagram • The most luminous ones are known as Cepheid variables: important for distance measureme ...
... brightness because they cannot achieve proper balance between power welling up from the core and power radiated from the surface • Most pulsating variable stars inhabit an instability strip on the H-R diagram • The most luminous ones are known as Cepheid variables: important for distance measureme ...
The Electromagnetic Spectrum
... you. • The train has a lower pitch when moving away from you. • This Doppler Effect is caused by compression or stretching of sound waves. • The same phenomenon occurs with light, only the ...
... you. • The train has a lower pitch when moving away from you. • This Doppler Effect is caused by compression or stretching of sound waves. • The same phenomenon occurs with light, only the ...
Hertzsprung-Russell Diagram, Flux, Luminosity, Magnitude—10 Oct Outline •
... of classifying spectra. Hertzsprung‐Russell diagram ...
... of classifying spectra. Hertzsprung‐Russell diagram ...
WHERE DO ELEMENTS COME FROM?
... • Knowledge gained in particle accelerators predicts the universe would produce 25% helium and 75% hydrogen in the first few minutes of creation. Nothing else. • These are stable – these proportions remain today. • Observations show the universe is now about 24% He, 74% H, 2% everything else • What ...
... • Knowledge gained in particle accelerators predicts the universe would produce 25% helium and 75% hydrogen in the first few minutes of creation. Nothing else. • These are stable – these proportions remain today. • Observations show the universe is now about 24% He, 74% H, 2% everything else • What ...
H-R Diagram Lab
... b. How does our sun compare to other stars in brightness and temperature? c. Are the stars scattered randomly on the graph, or is there a pattern? ...
... b. How does our sun compare to other stars in brightness and temperature? c. Are the stars scattered randomly on the graph, or is there a pattern? ...
Week 5 (10/16) – Quiz #11
... A. Wien’s law states that the temperature of a black body and the wavelength of peak radiation bear an inverse relation to each other B. The luminosity of a black body is proportional to its temperature raised to the fourth power C. Atoms are capable of absorbing and re-emitting photons D. The energ ...
... A. Wien’s law states that the temperature of a black body and the wavelength of peak radiation bear an inverse relation to each other B. The luminosity of a black body is proportional to its temperature raised to the fourth power C. Atoms are capable of absorbing and re-emitting photons D. The energ ...
AST 207 Test 2 26 October 2011
... The sun will be a main-sequence star for 10 Byr, and then it becomes a giant, which engulfs Earth. Therefore the sun will stay small for another 5 Byr. b. (2 pts.) Why does the helium in the core of the sun not fuse at the present time? (1 pt.) When that helium does fuse eventually, what will the he ...
... The sun will be a main-sequence star for 10 Byr, and then it becomes a giant, which engulfs Earth. Therefore the sun will stay small for another 5 Byr. b. (2 pts.) Why does the helium in the core of the sun not fuse at the present time? (1 pt.) When that helium does fuse eventually, what will the he ...
3.6 spectral classes
... The method of parallax is used in measuring the distances to nearby stars. The position of a star is carefully determined relative to other stars. Six months later, when Earth’s revolution has carried telescopes halfway around the Sun, the star’s position is measured again. Nearby stars appear to sh ...
... The method of parallax is used in measuring the distances to nearby stars. The position of a star is carefully determined relative to other stars. Six months later, when Earth’s revolution has carried telescopes halfway around the Sun, the star’s position is measured again. Nearby stars appear to sh ...
Faux Final
... scales? Label nucleus, bulge, and halo in the spheroid and disk. Illustrate spiral arms. Note the approximate position of the solar system. 10) Make a table of disk vs. spheroid for the Milky Way or other galaxies. List properties such as overall color, presence of gas, presence of dust, ages of the ...
... scales? Label nucleus, bulge, and halo in the spheroid and disk. Illustrate spiral arms. Note the approximate position of the solar system. 10) Make a table of disk vs. spheroid for the Milky Way or other galaxies. List properties such as overall color, presence of gas, presence of dust, ages of the ...
SHELL H II REGIONS IN NGC 6334
... As a matter of fact, surrounding the BNM/KL region, there is a well known molecular outflow with an upper limit of 1,000 years for its age. It is conceivable that the molecular outflow and the ejection of BN and I happened in the same event. The energy in the outflow is about 4X1047 ergs, that can ...
... As a matter of fact, surrounding the BNM/KL region, there is a well known molecular outflow with an upper limit of 1,000 years for its age. It is conceivable that the molecular outflow and the ejection of BN and I happened in the same event. The energy in the outflow is about 4X1047 ergs, that can ...
SN 2004dj
... Garnett et al. (1997) measured the metallity and its radial distribution in NGC 2403 ...
... Garnett et al. (1997) measured the metallity and its radial distribution in NGC 2403 ...
Neutron stars, pulsars
... Electron degeneracy cannot support a white dwarf heavier than 1.4 solar masses This is the “Chandrasekhar limit” Won Chandrasekhar the 1983 Nobel prize in Physics ...
... Electron degeneracy cannot support a white dwarf heavier than 1.4 solar masses This is the “Chandrasekhar limit” Won Chandrasekhar the 1983 Nobel prize in Physics ...
SCE 18 – Part 10
... • Matter (H and He) becomes sufficiently compressed to cause temperature to rise and start nuclear reactions. • In stars bigger than our sun, nuclear reactions produce nuclei of heavier elements up to iron. ...
... • Matter (H and He) becomes sufficiently compressed to cause temperature to rise and start nuclear reactions. • In stars bigger than our sun, nuclear reactions produce nuclei of heavier elements up to iron. ...
Test 2 - Constellations - ppt
... The constellations and the stars that make them up also appear in different locations throughout the year. ...
... The constellations and the stars that make them up also appear in different locations throughout the year. ...
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.