binary stars
... • As the energy leaks out, the central temperature of the Sun drops. • Lower temperature means lower gas pressure. • The lower gas pressure cannot hold up against gravity – the Sun shrinks. • The added compression puts the Sun’s center under greater pressure, so the central temperature increase ...
... • As the energy leaks out, the central temperature of the Sun drops. • Lower temperature means lower gas pressure. • The lower gas pressure cannot hold up against gravity – the Sun shrinks. • The added compression puts the Sun’s center under greater pressure, so the central temperature increase ...
Why are Binary Stars so Important for the Theory
... known very precisely. The photometric elements are derived by the classical Russell-Merrill method and by the modern model-simulation method by Wood. The two independent methods give consistent results and the radii of the two components are determined better than 1 %. The surface gravities are then ...
... known very precisely. The photometric elements are derived by the classical Russell-Merrill method and by the modern model-simulation method by Wood. The two independent methods give consistent results and the radii of the two components are determined better than 1 %. The surface gravities are then ...
School of Physics Multiwavelength Observations of Evolved Stars Research project in Astrophysics
... systems containing evolved giant stars with masses similar to that of our own Sun. Although supernovae are showy objects, stars with mass similar to our Sun are much more plentiful and when they evolve to the red giant stage they begin to lose processed material in the form of a cool wind. These sta ...
... systems containing evolved giant stars with masses similar to that of our own Sun. Although supernovae are showy objects, stars with mass similar to our Sun are much more plentiful and when they evolve to the red giant stage they begin to lose processed material in the form of a cool wind. These sta ...
PowerPoint Presentation - Research in observational
... the star cools and elements recombine reducing the thermal pressure. The star therefore contracts again to maintain equilibrium. • There is no hydrostatic equilibrium with a fully recombined star. • This results in a lower limit for stellar temperature. No star in hydrostatic equilibrium can be cool ...
... the star cools and elements recombine reducing the thermal pressure. The star therefore contracts again to maintain equilibrium. • There is no hydrostatic equilibrium with a fully recombined star. • This results in a lower limit for stellar temperature. No star in hydrostatic equilibrium can be cool ...
7.4 Evolution on the Main-Sequence Main-sequence (m
... H fusion, the whole star contracts in an attempt to maintain the energy production by increasing Tc . This produces a “left hook” in the HRD. The time spent in this phase is very short compared to the m-s phase. Hence very few stars are found in this final phase of m-s evolution. As H is exhausted, ...
... H fusion, the whole star contracts in an attempt to maintain the energy production by increasing Tc . This produces a “left hook” in the HRD. The time spent in this phase is very short compared to the m-s phase. Hence very few stars are found in this final phase of m-s evolution. As H is exhausted, ...
Part 2
... • At low T (solar center), the cycle is too slow to be important, but the C → N transformation is working. • Equivalent cycles involving Na and Mg exist and operate partially at higher temperature (≈ 5 · 107 K). • With increasing temperature, the CNO-cycle becomes more dominant. ...
... • At low T (solar center), the cycle is too slow to be important, but the C → N transformation is working. • Equivalent cycles involving Na and Mg exist and operate partially at higher temperature (≈ 5 · 107 K). • With increasing temperature, the CNO-cycle becomes more dominant. ...
MSci Astrophysics 210PHY412 - Queen's University Belfast
... Convective Overshooting One more important property of convection. What happens at the boundary between a convective region and non-convecitve region ? A rising convective element will still have a finite velocity as it enters the region where the convective criterion is not satisfied. This process ...
... Convective Overshooting One more important property of convection. What happens at the boundary between a convective region and non-convecitve region ? A rising convective element will still have a finite velocity as it enters the region where the convective criterion is not satisfied. This process ...
Building the Hertzsprung
... How hot? How old, and how long do they live? What is their chemical composition? How are they moving? Are they isolated or in clusters? By answering these questions, we not only learn about stars, but about the structure and evolution of galaxies they live in, and the ...
... How hot? How old, and how long do they live? What is their chemical composition? How are they moving? Are they isolated or in clusters? By answering these questions, we not only learn about stars, but about the structure and evolution of galaxies they live in, and the ...
![HR DIAGRAM[1] Star Human Comparison Are all stars the same](http://s1.studyres.com/store/data/010665051_1-e4f26b4aee29f3f3aaab891d368963d6-300x300.png)
HR DIAGRAM[1] Star Human Comparison Are all stars the same
... fuel to burn once the core of a star has been converted to iron. Iron cannot fuse and lose energy at the same time. Therefore, once the carbon is gone the temperature of the star’s core will drop. This causes the gas pressure to decrease. Then gravity has the upper hand, and the star will collapse u ...
... fuel to burn once the core of a star has been converted to iron. Iron cannot fuse and lose energy at the same time. Therefore, once the carbon is gone the temperature of the star’s core will drop. This causes the gas pressure to decrease. Then gravity has the upper hand, and the star will collapse u ...
Today`s Powerpoint
... Pattern of absorption lines depends on temperature (mainly) and chemical composition. Spectra give most accurate info on these as well as: density in atmosphere gravity at surface velocity of star towards or from us ...
... Pattern of absorption lines depends on temperature (mainly) and chemical composition. Spectra give most accurate info on these as well as: density in atmosphere gravity at surface velocity of star towards or from us ...
Chapter 10- Stars, Galaxies and the Universe
... 31. A device that detects radio waves from objects in space is called a(n) ____________________. 32. An object’s apparent change in position when viewed from two different places is called ____________________. 33. The length of a star’s life is determined by its ____________________. 34. A dying hi ...
... 31. A device that detects radio waves from objects in space is called a(n) ____________________. 32. An object’s apparent change in position when viewed from two different places is called ____________________. 33. The length of a star’s life is determined by its ____________________. 34. A dying hi ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
... Transport modes: radiation, convection, and conduction (which is only important in white dwarfs and stellar coronae). ...
... Transport modes: radiation, convection, and conduction (which is only important in white dwarfs and stellar coronae). ...
powerpoint - Physics @ IUPUI
... • A star is born when its core can finally generate energy via nuclear fusion. • This energy prevents the core from collapsing. • This is done by radiation pressure and gas pressure (they counteract gravity). • But to keep this up requires the constant generation of energy in the core. ...
... • A star is born when its core can finally generate energy via nuclear fusion. • This energy prevents the core from collapsing. • This is done by radiation pressure and gas pressure (they counteract gravity). • But to keep this up requires the constant generation of energy in the core. ...
Stars and Galaxies PP 2013
... High mass supergiants may undergo a supernova, where the core suddenly collapses and explodes. A neutron star is what remains after the supernova. It is composed mainly of neutrons and is very dense. If it spins and releases radiation it is called a pulsar. ...
... High mass supergiants may undergo a supernova, where the core suddenly collapses and explodes. A neutron star is what remains after the supernova. It is composed mainly of neutrons and is very dense. If it spins and releases radiation it is called a pulsar. ...
giant molecular clouds
... Energy generated in the star’s center must be transported to the surface. Inner layers: ...
... Energy generated in the star’s center must be transported to the surface. Inner layers: ...
Stars, Stellar classification, H
... Temperature Color Spectral Type Luminosity Radius *Mass *Lifespan ...
... Temperature Color Spectral Type Luminosity Radius *Mass *Lifespan ...
here - Atomki
... where κ is the (Rosseland) mean opacity (assuming radiative diffusion) - For conduction, the opacity is modified to include heat conduction - For convection, ∇ad= Pδ/(TρcP), (assuming adiabatic convection), which is a good approximation for stellar interiors but not the convective zones in the envel ...
... where κ is the (Rosseland) mean opacity (assuming radiative diffusion) - For conduction, the opacity is modified to include heat conduction - For convection, ∇ad= Pδ/(TρcP), (assuming adiabatic convection), which is a good approximation for stellar interiors but not the convective zones in the envel ...
Today`s Powerpoint
... fast depends on mass of H available and rate of fusion. Mass of H in core depends on mass of star. Fusion rate is related to luminosity (fusion reactions make the radiation energy). ...
... fast depends on mass of H available and rate of fusion. Mass of H in core depends on mass of star. Fusion rate is related to luminosity (fusion reactions make the radiation energy). ...
Where do Stars Form ?
... Formation of Stars Gas clouds have low temperatures, T~10-300 K with densities ranging from n ~ 5 x 108 m-3 to >1010 m-3. Stars form from the gravitational collapse of these clouds. What is the condition for collapse ? When does gravity overcome the gas pressure ? The Jeans Criterion Worked out by ...
... Formation of Stars Gas clouds have low temperatures, T~10-300 K with densities ranging from n ~ 5 x 108 m-3 to >1010 m-3. Stars form from the gravitational collapse of these clouds. What is the condition for collapse ? When does gravity overcome the gas pressure ? The Jeans Criterion Worked out by ...
HW11
... to the point that they start to gravitationally contract. We discussed 2 mechanisms that initiate star formation, and two mechanisms which continue star formation in the molecular cloud (self-sustained star formation) Be sure to understand how stellar life times, especially in the high mass O and B ...
... to the point that they start to gravitationally contract. We discussed 2 mechanisms that initiate star formation, and two mechanisms which continue star formation in the molecular cloud (self-sustained star formation) Be sure to understand how stellar life times, especially in the high mass O and B ...
Lecture 16
... In addition to hydrostatic equilibrium and an equation of state, one needs several additional equations. These describe the rate of energy generation by nuclear reactions, and transport of energy by convection. Those equations will not be discussed in this course. It is sufficient to know that they ...
... In addition to hydrostatic equilibrium and an equation of state, one needs several additional equations. These describe the rate of energy generation by nuclear reactions, and transport of energy by convection. Those equations will not be discussed in this course. It is sufficient to know that they ...
Star Life Cycle
... 15. Which has a longer life, bigger stars or smaller stars? Explain. ►Stars ►Stars: The beginning of the end. 16. When a star has burned off all of its __________________ and started to burn ______________, this is the beginning of the end. The burning of _________________releases a tremendous amoun ...
... 15. Which has a longer life, bigger stars or smaller stars? Explain. ►Stars ►Stars: The beginning of the end. 16. When a star has burned off all of its __________________ and started to burn ______________, this is the beginning of the end. The burning of _________________releases a tremendous amoun ...