Stars and Space - science
... • Particles gather under gravity to form a protostar. • The protostar becomes denser and hotter. If it reaches a point where hydrogen and other atoms fuse – huge amounts of energy (including light) are released and a star is born! AQA Science © Nelson Thornes Ltd 2006 ...
... • Particles gather under gravity to form a protostar. • The protostar becomes denser and hotter. If it reaches a point where hydrogen and other atoms fuse – huge amounts of energy (including light) are released and a star is born! AQA Science © Nelson Thornes Ltd 2006 ...
The correct answers are written in bold, italic and underlined. The
... gives an extra push as the star expands. • convection currents below the surface generate seismic waves that make the star oscillate in size. • nuclear reactions in the hydrogen-burning shell intensify when the star contracts, and the extra heat gives the gas a push as it expands. The star is like t ...
... gives an extra push as the star expands. • convection currents below the surface generate seismic waves that make the star oscillate in size. • nuclear reactions in the hydrogen-burning shell intensify when the star contracts, and the extra heat gives the gas a push as it expands. The star is like t ...
The Interstellar Medium (ISM)
... When a cloud starts to collapse, it should fragment. Fragments then collapse on their own, fragmenting further. End product is 100’s or 1000’s of dense clumps each destined to form star, binary star, etc. Hence a cloud gives birth to a cluster of stars. ...
... When a cloud starts to collapse, it should fragment. Fragments then collapse on their own, fragmenting further. End product is 100’s or 1000’s of dense clumps each destined to form star, binary star, etc. Hence a cloud gives birth to a cluster of stars. ...
DR 19.2 - Cobb Learning
... ______ 8. large, cool star in third stage of its life cycle 9. Explain how energy is generated in the core of a star during the second stage of its life cycle. _______________________________________________________________________________________________________ ____________________________________ ...
... ______ 8. large, cool star in third stage of its life cycle 9. Explain how energy is generated in the core of a star during the second stage of its life cycle. _______________________________________________________________________________________________________ ____________________________________ ...
The Properties of Stars
... The luminosity of a star is the total electromagnetic energy it emits in a unit of time. Two stars can have the same luminosity and very different apparent magnitudes. Alpha Centauri A and the Sun, for example, are both spectral class G2 stars and have about the same luminosity L = 3.86×1026 W. On t ...
... The luminosity of a star is the total electromagnetic energy it emits in a unit of time. Two stars can have the same luminosity and very different apparent magnitudes. Alpha Centauri A and the Sun, for example, are both spectral class G2 stars and have about the same luminosity L = 3.86×1026 W. On t ...
Lecture Ten - The Sun Amongst the Stars Part II
... some other process at work ‘removing’ hotter and more luminous stars from the populations we observe? The answer requires us to know how stars change over time, and therefore the ages of different stars – but this is by no means easy. All stars “live” a very long time (billions of years in most case ...
... some other process at work ‘removing’ hotter and more luminous stars from the populations we observe? The answer requires us to know how stars change over time, and therefore the ages of different stars – but this is by no means easy. All stars “live” a very long time (billions of years in most case ...
HEIC0619: EMBARGOED UNTIL: 19:30 (CET)/01:30 PM EST 11
... or maybe even more – tend to be born in multiple systems that can easily disguise themselves as single very heavy stars. Moreover, these stellar heavyweights are so rare that only a few are close enough to the Sun to be examined in detail. One of the top candidates for the title of “Milky Way stella ...
... or maybe even more – tend to be born in multiple systems that can easily disguise themselves as single very heavy stars. Moreover, these stellar heavyweights are so rare that only a few are close enough to the Sun to be examined in detail. One of the top candidates for the title of “Milky Way stella ...
Luminosity and brightness
... radius R is 4R2. A star with a radius of 2R will therefore have four times the luminosity of a star of radius R if the stars are at the same temperature. The luminosity of a star also depends on its temperature. If we consider a star to be a perfect black body then the radiation emitted per second ...
... radius R is 4R2. A star with a radius of 2R will therefore have four times the luminosity of a star of radius R if the stars are at the same temperature. The luminosity of a star also depends on its temperature. If we consider a star to be a perfect black body then the radiation emitted per second ...
PoA Examples Sheet 3
... 7. A source of ionising radiation is located at a distance R from a star surrounded by a neutral protoplanetary disc. A neutral disc wind feeds gas into an ionisation front which cuts the line between the star and the ionising source at at a distance rI from the star. Explain why (in the limit R >> ...
... 7. A source of ionising radiation is located at a distance R from a star surrounded by a neutral protoplanetary disc. A neutral disc wind feeds gas into an ionisation front which cuts the line between the star and the ionising source at at a distance rI from the star. Explain why (in the limit R >> ...
Stellar Forces
... Flux(at radius r) = Lr/4r2 = -D dUr/dr where Ur is energy density in radiation = aT4 (a is radiation constant 7.6 x 10-16 J m-3 K-4) and D = 1/3 c where is mean free path of photons). Need to know what fraction photons absorbed - defined through so that dl gives fraction energy lost by absor ...
... Flux(at radius r) = Lr/4r2 = -D dUr/dr where Ur is energy density in radiation = aT4 (a is radiation constant 7.6 x 10-16 J m-3 K-4) and D = 1/3 c where is mean free path of photons). Need to know what fraction photons absorbed - defined through so that dl gives fraction energy lost by absor ...
Requiem for a Star
... • Requires increasingly higher temperatures and pressures – Requires more gravitational collapse = more mass ...
... • Requires increasingly higher temperatures and pressures – Requires more gravitational collapse = more mass ...
ASTRONOMY 0089: EXAM 2 Class Meets M,W,F, 1:00 PM Mar 22
... 20. To which region of the Sun does the following refer? It is an inhomogeneous and tenuous region with a temperature of more than 106 K (1 millionK). At visible wavelengths it is best studied during a Solar eclipse. a. the chromosphere. b. the core c. the photosphere d. the convective zone. e. the ...
... 20. To which region of the Sun does the following refer? It is an inhomogeneous and tenuous region with a temperature of more than 106 K (1 millionK). At visible wavelengths it is best studied during a Solar eclipse. a. the chromosphere. b. the core c. the photosphere d. the convective zone. e. the ...
OVERVIEW ABSTRACT HST/COS chemical abundance analysis of
... 12-13 billion years Low-mass stars still found in the Galactic Halo today! ...
... 12-13 billion years Low-mass stars still found in the Galactic Halo today! ...
Classes 12 to 13 - physics.udel.edu
... White dwarf cooling – Mestel theory A white dwarf has an electron degenerate core with a thin non-degenerate envelope (m ≈ 10-4 M☉). In the core the electrons have a large mean free path because almost all available energy levels in the Fermi ‘sea’ are filled. This results in a high thermal conducti ...
... White dwarf cooling – Mestel theory A white dwarf has an electron degenerate core with a thin non-degenerate envelope (m ≈ 10-4 M☉). In the core the electrons have a large mean free path because almost all available energy levels in the Fermi ‘sea’ are filled. This results in a high thermal conducti ...
Lecture 19 Brightness Units
... are all due to absorption by atoms starting from the second energy state. – The only way an atom gets into this state is by being hit by a neighbor, and the neighbors at these temperatures are not moving fast enough. Balmer lines are weak. Mar 3, 2006 ...
... are all due to absorption by atoms starting from the second energy state. – The only way an atom gets into this state is by being hit by a neighbor, and the neighbors at these temperatures are not moving fast enough. Balmer lines are weak. Mar 3, 2006 ...
HW #8 Stellar Evolution I Solutions
... luminosity, radius and temperature while on the main sequence, because of the natural thermostat mechanism in main sequence stars. The thermostat mechanism acts to return the core fusion rates back to an equilibrium rate in the event of fluctuations in the core fusion rate. This is known as a negati ...
... luminosity, radius and temperature while on the main sequence, because of the natural thermostat mechanism in main sequence stars. The thermostat mechanism acts to return the core fusion rates back to an equilibrium rate in the event of fluctuations in the core fusion rate. This is known as a negati ...
Slide 1 - Personal.psu.edu
... Planetary formation has begun, but the protostar is still not in equilibrium—all heating comes from the gravitational collapse. ...
... Planetary formation has begun, but the protostar is still not in equilibrium—all heating comes from the gravitational collapse. ...
Teacher Guide Lives of Stars
... to make the groups of different skill levels. Each student in each group will take turns reading so that everyone has to read and follow their script. ...
... to make the groups of different skill levels. Each student in each group will take turns reading so that everyone has to read and follow their script. ...
Star formation - Grosse Pointe Public School System
... stabilizes. This is called hydrostatic equilibrium. • This balance of fusion vs. gravitational forces keeps the star a stable size until late in its life. During this time, the star is on the Main Sequence of the H-R Diagram. ...
... stabilizes. This is called hydrostatic equilibrium. • This balance of fusion vs. gravitational forces keeps the star a stable size until late in its life. During this time, the star is on the Main Sequence of the H-R Diagram. ...
The structure and evolution of stars
... Stars are held together by gravitation – attraction exerted on each part of the star by all other parts Collapse is resisted by internal thermal pressure. These two forces play the principal role in determining stellar structure – they must be (at least almost) in balance Thermal properties of stars ...
... Stars are held together by gravitation – attraction exerted on each part of the star by all other parts Collapse is resisted by internal thermal pressure. These two forces play the principal role in determining stellar structure – they must be (at least almost) in balance Thermal properties of stars ...
Star formation slides
... k = Boltzmann’s constant T = temperature In order to get the highest gravity, we need lots of mass (density) Therefore, in order to get the lowest gas pressure, we need the lowest T. Stars are born in very cold clouds (~10100 K). ...
... k = Boltzmann’s constant T = temperature In order to get the highest gravity, we need lots of mass (density) Therefore, in order to get the lowest gas pressure, we need the lowest T. Stars are born in very cold clouds (~10100 K). ...
Chapter 13 (Properties of Stars)
... 22. When heliocentric parallax is measured, a LARGE parallax means that the star is: A. relatively far away. B. small in radius. C. relatively close by. D. not very bright. 23. On the H-R diagram for stars in general, a lower mass star may be found: A. at higher luminosity and lower temperature. B. ...
... 22. When heliocentric parallax is measured, a LARGE parallax means that the star is: A. relatively far away. B. small in radius. C. relatively close by. D. not very bright. 23. On the H-R diagram for stars in general, a lower mass star may be found: A. at higher luminosity and lower temperature. B. ...