black hole - Purdue Physics
... The amount of energy released is so great, that most of the elements heavier than Fe are instantly created ...
... The amount of energy released is so great, that most of the elements heavier than Fe are instantly created ...
Physics 3 Revision GUide
... The mechanisms and processes involved when earthquakes occur are extremely complex. However some of the characteristics of earthquakes can be explained: ...
... The mechanisms and processes involved when earthquakes occur are extremely complex. However some of the characteristics of earthquakes can be explained: ...
Slide 1
... Comprised of 2 stars in a close orbit around each other (i.e., a binary system). They are tidally locked (i.e., rotation period equals orbital period, of only days). ...
... Comprised of 2 stars in a close orbit around each other (i.e., a binary system). They are tidally locked (i.e., rotation period equals orbital period, of only days). ...
SUMMARY OF KEY CONCEPTS: GALAXIES AND COSMOLOGY
... direction toward which our galaxy is moving, and cooler in the opposite direction. (2) If this is subtracted, there’s an even smaller pattern of ripples with hot and cool spots that are a few parts in 100,000 different from the mean temperature. These anisotropies are the seeds from which galaxies a ...
... direction toward which our galaxy is moving, and cooler in the opposite direction. (2) If this is subtracted, there’s an even smaller pattern of ripples with hot and cool spots that are a few parts in 100,000 different from the mean temperature. These anisotropies are the seeds from which galaxies a ...
Unit 1 – Electromagnetism
... The mechanisms and processes involved when earthquakes occur are extremely complex. However some of the characteristics of earthquakes can be explained: ...
... The mechanisms and processes involved when earthquakes occur are extremely complex. However some of the characteristics of earthquakes can be explained: ...
ultracam observations of pulsating sdB stars
... origin of sdB stars Binary evolution is important in at least 2/3 of sdBs (Green, Liebert & Saffer, 2001, ASP 226). Key factor is Roche Lobe Overflow in metal-rich low-mass giants near the Red Giant Tip. Group III (composite) sdBs are the key: i. low-mass binary with initial separation 415-520 R ii ...
... origin of sdB stars Binary evolution is important in at least 2/3 of sdBs (Green, Liebert & Saffer, 2001, ASP 226). Key factor is Roche Lobe Overflow in metal-rich low-mass giants near the Red Giant Tip. Group III (composite) sdBs are the key: i. low-mass binary with initial separation 415-520 R ii ...
nuclear reactions in stars: theoretical and experimental
... model") can be used for capture reactions [?]. Heavy-ion fusion reactions are also described by this model, even if different variants exit [?]. An extension of the standard optical model is the Distorted Wave Born Approximation (DWBA, see Ref. [?]), used to describe transfer processes such as (α,n) ...
... model") can be used for capture reactions [?]. Heavy-ion fusion reactions are also described by this model, even if different variants exit [?]. An extension of the standard optical model is the Distorted Wave Born Approximation (DWBA, see Ref. [?]), used to describe transfer processes such as (α,n) ...
IPHAS: Surveying the Northern Galactic Plane in Hα
... Mampaso in Spain. Its goal is to conduct an Hα survey of the entire northern Galactic Plane in the latitude range – 5°< b< +5°, a sky area of 1800 sq. deg., covering the magnitude range 13 < r'< 20. That such a survey is ...
... Mampaso in Spain. Its goal is to conduct an Hα survey of the entire northern Galactic Plane in the latitude range – 5°< b< +5°, a sky area of 1800 sq. deg., covering the magnitude range 13 < r'< 20. That such a survey is ...
High-Resolution Spectroscopy of the Transiting Planet Host Star
... prevents the determination of an absolute luminosity. In addition, as the star does not show signs of evolution off the main sequence, the surface gravity constitutes a poor constraint for the models. The effective temperature and metallicity, together with an age estimate as we discuss below, are t ...
... prevents the determination of an absolute luminosity. In addition, as the star does not show signs of evolution off the main sequence, the surface gravity constitutes a poor constraint for the models. The effective temperature and metallicity, together with an age estimate as we discuss below, are t ...
Selected topics in Nuclear Astrophysics
... as well as of the various nuclear processes, occurring in and powering astrophysical objects, which lead to the production of elements. It is impossible to cover the large width of this truely interdisciplinary field in these lectures. Hence I have made a biased choice and concentrate in the followi ...
... as well as of the various nuclear processes, occurring in and powering astrophysical objects, which lead to the production of elements. It is impossible to cover the large width of this truely interdisciplinary field in these lectures. Hence I have made a biased choice and concentrate in the followi ...
Early Universe and Thermal History
... brief periods of non equilibrium and these are responsible for our Universe being populated with particles (in addition to photons). In other words, there were epochs when the rate of Universe expansion exceeded the rate of reactions that kept particles tied to the radiation field. If the rate Γ of ...
... brief periods of non equilibrium and these are responsible for our Universe being populated with particles (in addition to photons). In other words, there were epochs when the rate of Universe expansion exceeded the rate of reactions that kept particles tied to the radiation field. If the rate Γ of ...
Stellar Helium Burning in Other Universes: A
... retains an appreciable supply of 4 He, carbon can be produced in subsequent stellar generations through the reaction 4 He + 8 Be → 12 C. This reaction is a natural channel to produce carbon — alpha particles are energetically favorable states, so that isotopes produced by adding together alpha parti ...
... retains an appreciable supply of 4 He, carbon can be produced in subsequent stellar generations through the reaction 4 He + 8 Be → 12 C. This reaction is a natural channel to produce carbon — alpha particles are energetically favorable states, so that isotopes produced by adding together alpha parti ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
... evolution of more distant galaxies to date (Matteucci & Tosi 1985). So far, only a very limited number of elements can be examined and quantified when using this approach. The chemical evolution of a galaxy depends on the contributions of all its constituents, e.g., SNe type Ia and II, high mass sta ...
... evolution of more distant galaxies to date (Matteucci & Tosi 1985). So far, only a very limited number of elements can be examined and quantified when using this approach. The chemical evolution of a galaxy depends on the contributions of all its constituents, e.g., SNe type Ia and II, high mass sta ...
NAME
... d. they contain lots of dust e. they contain a mix of old and young stars ____ 12. The disks of spiral galaxies appear blue because: a. they are moving toward us b. they contain a relatively high concentration of low-mass stars c. they contain active regions of star formation d. they contain more me ...
... d. they contain lots of dust e. they contain a mix of old and young stars ____ 12. The disks of spiral galaxies appear blue because: a. they are moving toward us b. they contain a relatively high concentration of low-mass stars c. they contain active regions of star formation d. they contain more me ...
This is the Title - Astronomy at Swarthmore College
... core with helium and then hydrogen in shells around the core. Helium burning occurs in short phases when conditions become suitable. These helium flashes create convection zones, which permit the carbon and oxygen from the core to move to the surface. Upon reaching the star’s surface, the metals are ...
... core with helium and then hydrogen in shells around the core. Helium burning occurs in short phases when conditions become suitable. These helium flashes create convection zones, which permit the carbon and oxygen from the core to move to the surface. Upon reaching the star’s surface, the metals are ...
Contents and structure of the Milky Way I
... in a particular wavelength range corresponding to the filter on our telescope, not its total luminosity at all wavelengths (the total luminosity is known as bolometric luminosity). Some common filters are B (blue), V (visible, which is green, more or less), R (red) and I (redder than R). Absolute ma ...
... in a particular wavelength range corresponding to the filter on our telescope, not its total luminosity at all wavelengths (the total luminosity is known as bolometric luminosity). Some common filters are B (blue), V (visible, which is green, more or less), R (red) and I (redder than R). Absolute ma ...
jbrown_keck - Astronomy at Swarthmore College
... core with helium and then hydrogen in shells around the core. Helium burning occurs in short phases when conditions become suitable. These helium flashes create convection zones, which permit the carbon and oxygen from the core to move to the surface. Upon reaching the star’s surface, the metals are ...
... core with helium and then hydrogen in shells around the core. Helium burning occurs in short phases when conditions become suitable. These helium flashes create convection zones, which permit the carbon and oxygen from the core to move to the surface. Upon reaching the star’s surface, the metals are ...
No Slide Title
... Supernovae as Standard Candles • The brightest supernovae reach M = -19 at the peak of their output. In theory they can be seen up to 8000 Mly from Earth. This makes them potentially very interesting as Standard Candles. • Supernovae are divided into various types. Type 1 are thought to be formed b ...
... Supernovae as Standard Candles • The brightest supernovae reach M = -19 at the peak of their output. In theory they can be seen up to 8000 Mly from Earth. This makes them potentially very interesting as Standard Candles. • Supernovae are divided into various types. Type 1 are thought to be formed b ...
The Milky Way
... solar masses Additional mass in an extended halo: Total: Approx. 1 trillion solar masses Most of the mass is not emitting any radiation: ...
... solar masses Additional mass in an extended halo: Total: Approx. 1 trillion solar masses Most of the mass is not emitting any radiation: ...
–1– 1. Stellar Evolution For Massive Stars 1.1. The Importance of
... during the main sequence phase is proportional to ∆M/M ∝ M 1.8 . Because of this strong dependence on mass, mass loss becomes very important for high mass stars. If high mass 0Z stars really do have very weak winds, they will not be very effective at polluting the ISM with nuclear processed material ...
... during the main sequence phase is proportional to ∆M/M ∝ M 1.8 . Because of this strong dependence on mass, mass loss becomes very important for high mass stars. If high mass 0Z stars really do have very weak winds, they will not be very effective at polluting the ISM with nuclear processed material ...
Chapter 44 Problems
... electrons to form a neutron star. Such a star could be thought of as a gigantic atomic nucleus. If a star of mass 2 × 1.99 × 1030 kg collapsed into neutrons (mn = 1.67 × 10–27 kg), what would its radius be? (Assume that r = r0A1/3.) ...
... electrons to form a neutron star. Such a star could be thought of as a gigantic atomic nucleus. If a star of mass 2 × 1.99 × 1030 kg collapsed into neutrons (mn = 1.67 × 10–27 kg), what would its radius be? (Assume that r = r0A1/3.) ...
Living alongside Monsters: Matter around Central Massive Black Holes Q. Daniel Wang
... • The mass-loaded hot gas undergoes outflows, affecting the global ecosystem of the galaxies. • We aim to understand the formation modes of massive stars and their interplay with the extreme environment in galactic nuclei. ...
... • The mass-loaded hot gas undergoes outflows, affecting the global ecosystem of the galaxies. • We aim to understand the formation modes of massive stars and their interplay with the extreme environment in galactic nuclei. ...
RED DWARFS AND THE END OF THE MAIN SEQUENCE
... never have a helium flash and the lightcurve falls off gently for about 7 trillion years as the lowest mass stars slowly die. During this time, the galaxy should look quite blue, because the light is dominated by stars that have aborted their journey up the red giant branch and grown bluer. Finally, ...
... never have a helium flash and the lightcurve falls off gently for about 7 trillion years as the lowest mass stars slowly die. During this time, the galaxy should look quite blue, because the light is dominated by stars that have aborted their journey up the red giant branch and grown bluer. Finally, ...
16-2 Enrich: More Properties of Metals
... You have learned that each group of the periodic table has similar properties. For example, the metals of Group 1 are so reactive they don’t exist uncombined in nature. The Group 2 metals are also quite reactive. The table below shows atomic radius and reactivity of most of the metals in Groups 1 an ...
... You have learned that each group of the periodic table has similar properties. For example, the metals of Group 1 are so reactive they don’t exist uncombined in nature. The Group 2 metals are also quite reactive. The table below shows atomic radius and reactivity of most of the metals in Groups 1 an ...
Ch. 26.5: The Expanding Universe
... Exerts gravitational force on visible matter Universe may be 90% + dark matter Why do we think Dark Matter exists? Galaxies are accelerating faster than they should be (based on the observable matter in the Universe). The acceleration due to gravity does not match up with the amount of matter that w ...
... Exerts gravitational force on visible matter Universe may be 90% + dark matter Why do we think Dark Matter exists? Galaxies are accelerating faster than they should be (based on the observable matter in the Universe). The acceleration due to gravity does not match up with the amount of matter that w ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.