Lecture 9
... Stars are metal rich More metals made in supernova New stars have less and less hydrogen as they become polluted with metals Mass is getting locked up in white dwarfs, neutron stars and black holes! ...
... Stars are metal rich More metals made in supernova New stars have less and less hydrogen as they become polluted with metals Mass is getting locked up in white dwarfs, neutron stars and black holes! ...
NCEA Level 2 Earth and Space Science (91192) 2013
... fuel source is hydrogen fusing to helium • red giant • planetary nebula • white dwarf. The birth stage is explained: GMC condenses under gravity. As it condenses, the particles become hotter (due to friction) and eventually become hot enough to become a protostar. Aldebaran birth explained with asso ...
... fuel source is hydrogen fusing to helium • red giant • planetary nebula • white dwarf. The birth stage is explained: GMC condenses under gravity. As it condenses, the particles become hotter (due to friction) and eventually become hot enough to become a protostar. Aldebaran birth explained with asso ...
NCEA Level 2 Earth and Space Science (91192)
... fuel source is hydrogen fusing to helium • red giant • planetary nebula • white dwarf. The birth stage is explained: GMC condenses under gravity. As it condenses, the particles become hotter (due to friction) and eventually become hot enough to become a protostar. Aldebaran birth explained with asso ...
... fuel source is hydrogen fusing to helium • red giant • planetary nebula • white dwarf. The birth stage is explained: GMC condenses under gravity. As it condenses, the particles become hotter (due to friction) and eventually become hot enough to become a protostar. Aldebaran birth explained with asso ...
Lecture Notes
... A second class of supernova arises from the entirely distinct process of accretion onto a white dwarf in a binary system. As the mass approaches the ‘Chandrasekhar limit’ of 1.4M , the increasing temperature and density results in ignition of carbon fusion. This proceeds very rapidly, releasing hug ...
... A second class of supernova arises from the entirely distinct process of accretion onto a white dwarf in a binary system. As the mass approaches the ‘Chandrasekhar limit’ of 1.4M , the increasing temperature and density results in ignition of carbon fusion. This proceeds very rapidly, releasing hug ...
C, N, O abundances and carbon isotope ratios in evolved stars of
... used a photometric method. To make our study as homogeneous as possible, we decided to redetermine them spectroscopically. The spectroscopic effective temperatures were derived by minimising the slope of the abundances obtained from neutral Fe i lines with respect to the excitation potential. The gra ...
... used a photometric method. To make our study as homogeneous as possible, we decided to redetermine them spectroscopically. The spectroscopic effective temperatures were derived by minimising the slope of the abundances obtained from neutral Fe i lines with respect to the excitation potential. The gra ...
The fate of black hole singularities and the parameters of the
... holes in the observable universe is likely to be as high as one hundred per second1 , this may be taken to be the rate at which our ignorance about the universe is increasing due to our not knowing what lies behind all of these event horizons. When one adds quantum physics to the picture the puzzle ...
... holes in the observable universe is likely to be as high as one hundred per second1 , this may be taken to be the rate at which our ignorance about the universe is increasing due to our not knowing what lies behind all of these event horizons. When one adds quantum physics to the picture the puzzle ...
Pulsars
... The canonical neutron star has M~ 1.4MSun and R~ 10 km, depending on the equation-of-state of extremely dense matter composed of neutrons, quarks, etc. The extreme density and pressure turns most of the star into a neutron superfluid that is a superconductor up to temperatures T~109 K. Any star of s ...
... The canonical neutron star has M~ 1.4MSun and R~ 10 km, depending on the equation-of-state of extremely dense matter composed of neutrons, quarks, etc. The extreme density and pressure turns most of the star into a neutron superfluid that is a superconductor up to temperatures T~109 K. Any star of s ...
The Universe - Cloudfront.net
... a. a dark, cool interstellar cloud begins to contract b. a protostar reaches a temperature high enough for nuclear fusion to begin c. pressure within a protostar becomes so great that a supernova occurs d. a red giant collapses on itself and becomes a black hole 3) Which force is most responsible fo ...
... a. a dark, cool interstellar cloud begins to contract b. a protostar reaches a temperature high enough for nuclear fusion to begin c. pressure within a protostar becomes so great that a supernova occurs d. a red giant collapses on itself and becomes a black hole 3) Which force is most responsible fo ...
Mechanical and thermodynamical properties of matter in strong
... White dwarfs, neutron stars and black holes are examples of compact stars. Also exotic stars, which are a compact star composed of something other than baryons as darkmatter. Compact stars are stellar objects with small volume for their mass, which means very high density. For instance, neutron star ...
... White dwarfs, neutron stars and black holes are examples of compact stars. Also exotic stars, which are a compact star composed of something other than baryons as darkmatter. Compact stars are stellar objects with small volume for their mass, which means very high density. For instance, neutron star ...
Teacher`s Guide - Cornell Science Inquiry Partnerships
... New York State Standards (Physical Setting/Earth Science Standards) o Standard 1: Analysis, Inquiry, and Design: Scientific Inquiry Key Idea 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process. Key Idea 2: Beyond the use ...
... New York State Standards (Physical Setting/Earth Science Standards) o Standard 1: Analysis, Inquiry, and Design: Scientific Inquiry Key Idea 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process. Key Idea 2: Beyond the use ...
Astronomy 321 --- Homework Exercise: Star Wheel
... In the tables below, the first column is the constellation, with its standard 3-letter abbreviation in parentheses. For constellations with bright stars, one or two of these bright stars are listed in the 2nd column and should also be learned. The 3rd column lists other objects of interest (e.g., st ...
... In the tables below, the first column is the constellation, with its standard 3-letter abbreviation in parentheses. For constellations with bright stars, one or two of these bright stars are listed in the 2nd column and should also be learned. The 3rd column lists other objects of interest (e.g., st ...
Chromospherically young, kinematically old stars
... Received 3 July 2001 / Accepted 18 December 2001 Abstract. We have investigated a group of stars known to have low chromospheric ages, but high kinematical ages. Isochrone, chemical and lithium ages are estimated for them. The majority of stars in this group show lithium abundances much smaller than ...
... Received 3 July 2001 / Accepted 18 December 2001 Abstract. We have investigated a group of stars known to have low chromospheric ages, but high kinematical ages. Isochrone, chemical and lithium ages are estimated for them. The majority of stars in this group show lithium abundances much smaller than ...
UMich w/s - Royal Observatory, Edinburgh
... Either (i) determine mass profile from projected dispersion profile, with assumed isotropy, and smooth functional fit to the light profile Or (ii) assume a parameterised mass model M(r) and velocity dispersion anisotropy β(r) and fit dispersion profile to find best forms of these (for fixed light ...
... Either (i) determine mass profile from projected dispersion profile, with assumed isotropy, and smooth functional fit to the light profile Or (ii) assume a parameterised mass model M(r) and velocity dispersion anisotropy β(r) and fit dispersion profile to find best forms of these (for fixed light ...
ATA2010
... by supernovae and AGB stars - many cycles of enrichment give chemical evolution up to the present level of chemical abundance - SN and AGB stars Two main kinds of supernovae: SNII (progenitor M > 8M) produce -elements (O, Mg, Si, Ca,Ti), some Fe-peak elements (V … Zn), and r-process elements (eg E ...
... by supernovae and AGB stars - many cycles of enrichment give chemical evolution up to the present level of chemical abundance - SN and AGB stars Two main kinds of supernovae: SNII (progenitor M > 8M) produce -elements (O, Mg, Si, Ca,Ti), some Fe-peak elements (V … Zn), and r-process elements (eg E ...
New Mass Loss Measurements from Astrospheric Lyα Absorption
... assumption of the same 400 km s⫺1 wind speed in all astrospheric models (akin to solar low-speed streams) is another major source of uncertainty, its justification being that one might expect similar wind speeds from stars with similar spectral types and surface escape speeds (Wood 2004). Figure 1 c ...
... assumption of the same 400 km s⫺1 wind speed in all astrospheric models (akin to solar low-speed streams) is another major source of uncertainty, its justification being that one might expect similar wind speeds from stars with similar spectral types and surface escape speeds (Wood 2004). Figure 1 c ...
The dramatic change of the fossil magnetic field of HD 190073
... of these fields in very young stars, and to the lack of characteristics that could be linked to a dynamo, these fields are believed either to be remnants of the Galactic fields that would have been swept up by the contracting core, or to have been generated by a dynamo when part of the star was conv ...
... of these fields in very young stars, and to the lack of characteristics that could be linked to a dynamo, these fields are believed either to be remnants of the Galactic fields that would have been swept up by the contracting core, or to have been generated by a dynamo when part of the star was conv ...
PH607lec11-4gal2
... Note that density wave theory does not explain flocculent spirals. Those can be explained by self-propagating star formation: Star forming regions produce supernovae, which shocks the gas, which triggers more star formation, etc, etc, etc Differential rotation stretches out the regions of star forma ...
... Note that density wave theory does not explain flocculent spirals. Those can be explained by self-propagating star formation: Star forming regions produce supernovae, which shocks the gas, which triggers more star formation, etc, etc, etc Differential rotation stretches out the regions of star forma ...
Big Bang Theory - Clark Planetarium
... • Protons, anti-protons, neutrons and anti-neutrons begin to form • As a proton or neutron collides with its anti-particle they annihilate and are converted to energy in the form of photons ...
... • Protons, anti-protons, neutrons and anti-neutrons begin to form • As a proton or neutron collides with its anti-particle they annihilate and are converted to energy in the form of photons ...
Lecture 9
... nuclei such as deuterium (D), helium-3 (3 He), helium-4 (4 He) and lithium-7 (7 Li) containing three protons and four neutrons. Nucleosynthesis takes place because it is energetically favorable. When a neutron and proton are bound together to form deuterium, energy is released: p + n → D + 2.22 MeV ...
... nuclei such as deuterium (D), helium-3 (3 He), helium-4 (4 He) and lithium-7 (7 Li) containing three protons and four neutrons. Nucleosynthesis takes place because it is energetically favorable. When a neutron and proton are bound together to form deuterium, energy is released: p + n → D + 2.22 MeV ...
Intro to the Night Sky - AST 114, Astronomy Lab II for Spring 2017!
... named on your star wheel or in the Audubon Guide. One realizes that if all 6000 naked eye stars and the enormous number of fainter stars all had proper names, nobody would be able to figure out which star someone was talking about. Astronomers developed a naming system for the brighter stars. The st ...
... named on your star wheel or in the Audubon Guide. One realizes that if all 6000 naked eye stars and the enormous number of fainter stars all had proper names, nobody would be able to figure out which star someone was talking about. Astronomers developed a naming system for the brighter stars. The st ...
gravitation - Sakshieducation.com
... g) The more massive a star is, faster will be the rate at which it will use its fuel because greater energy is required to balance the greater gravitational attraction, owing to greater mass i.e. massive stars burn out quickly. h) When the nuclear fuel is over, i.e. when the star cools off, the radi ...
... g) The more massive a star is, faster will be the rate at which it will use its fuel because greater energy is required to balance the greater gravitational attraction, owing to greater mass i.e. massive stars burn out quickly. h) When the nuclear fuel is over, i.e. when the star cools off, the radi ...
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.