AST1100 Lecture Notes
... When the hydrogen in the core has been exhausted, the forces of pressure are not any longer strong enough to sustain the forces of gravity. The hydrostatic equilibrium is lost and the core starts contracting. During the core contraction, the temperature in and around the core increases. The tempera ...
... When the hydrogen in the core has been exhausted, the forces of pressure are not any longer strong enough to sustain the forces of gravity. The hydrostatic equilibrium is lost and the core starts contracting. During the core contraction, the temperature in and around the core increases. The tempera ...
10.2 Galaxies
... • If the nebula cloud is massive enough, gravity within the cloud will be large enough to shrink it and to raise its temperature above 10 000 000 degrees celsius, a temperature at which atomic fusion happens, releasing huge amounts of energy in the form of all kinds of electromagnetic radiation (gam ...
... • If the nebula cloud is massive enough, gravity within the cloud will be large enough to shrink it and to raise its temperature above 10 000 000 degrees celsius, a temperature at which atomic fusion happens, releasing huge amounts of energy in the form of all kinds of electromagnetic radiation (gam ...
N Brickhouse
... Ne varies only slightly. • Variable Te means rt changes. • Assuming NH is from pre-shock gas, we can get path length
and thus the filling factor.
...
... Ne varies only slightly. • Variable Te means rt changes. • Assuming NH is from pre-shock gas, we can get path length
Giant Stars
... •For stars from 0.5 to 3 MSun, it is qualitatively the same •Heavy stars do everything faster •For heavier stars, some details are different •Higher temperature and lower density •Core isn’t so compact •No dramatic increase in luminosity •Motion on the H-R diagram is mostly ...
... •For stars from 0.5 to 3 MSun, it is qualitatively the same •Heavy stars do everything faster •For heavier stars, some details are different •Higher temperature and lower density •Core isn’t so compact •No dramatic increase in luminosity •Motion on the H-R diagram is mostly ...
Astronomy 535 Stellar Structure Evolution
... evolution • Evolution of ISM, IGM, gas fraction, composition, star formation, populations, galaxies, baryonic matter in general profoundly depends on stellar evolution • Fits of models to observations by means of free parameters is standard procedure, but gives unreliable or downright bad results fo ...
... evolution • Evolution of ISM, IGM, gas fraction, composition, star formation, populations, galaxies, baryonic matter in general profoundly depends on stellar evolution • Fits of models to observations by means of free parameters is standard procedure, but gives unreliable or downright bad results fo ...
Aldebaran
... condense further and heat up. Nuclear reactions occurred when the temperature in the center of the protostar reached about 10 million degrees, and the star was born. Further expansion and heating of the star’s exterior then led to the formation of a red giant. This is what Aldebaran is now. Aldebara ...
... condense further and heat up. Nuclear reactions occurred when the temperature in the center of the protostar reached about 10 million degrees, and the star was born. Further expansion and heating of the star’s exterior then led to the formation of a red giant. This is what Aldebaran is now. Aldebara ...
Components of the Milky Way
... fusion of H -> He. Contraction ceases - main sequence phase. Estimate the main-sequence lifetime: • Fusion of H to He yields e = 6 x 1018 erg / g • Solar mass is Msun = 2 x 1033 g • Solar luminosity is Lsun = 3.9 x 1033 erg / s • Mass fraction of hydrogen in the Sun X = 0.7 • Stars leave the main se ...
... fusion of H -> He. Contraction ceases - main sequence phase. Estimate the main-sequence lifetime: • Fusion of H to He yields e = 6 x 1018 erg / g • Solar mass is Msun = 2 x 1033 g • Solar luminosity is Lsun = 3.9 x 1033 erg / s • Mass fraction of hydrogen in the Sun X = 0.7 • Stars leave the main se ...
The Voronoi tessellation generated from different
... In order to understand better the differences between the three types of seeds we review in table 1 the family parameters. We should stress that in a previous analysis [ 7 ] a value of c z 4 has been extracted for the r distribution and random seeds. We find a similar value, c= 3.37, but the lognorm ...
... In order to understand better the differences between the three types of seeds we review in table 1 the family parameters. We should stress that in a previous analysis [ 7 ] a value of c z 4 has been extracted for the r distribution and random seeds. We find a similar value, c= 3.37, but the lognorm ...
Document
... number of astrophysical phenomena which are otherwise difficult to understand. Binaries provide an explanation for Type Ia supernovae. These are thought to be a consequence of accretion onto a white dwarf. Binaries explain why the progenitor of SN1987A was a blue supergiant: its outer envelope was l ...
... number of astrophysical phenomena which are otherwise difficult to understand. Binaries provide an explanation for Type Ia supernovae. These are thought to be a consequence of accretion onto a white dwarf. Binaries explain why the progenitor of SN1987A was a blue supergiant: its outer envelope was l ...
Kamiokande and Super-Kamiokande Results on Neutrino
... – KAM observed deficit of solar neutrinos, and SK contributed to the evidence for the solar neutrino oscillation and parameter determination. – Neutrinos from SN1987A by KAM, and a large statistical observation of galactic supernova is expected in SK. – Atmospheric neutrino anomaly in KAM, and evide ...
... – KAM observed deficit of solar neutrinos, and SK contributed to the evidence for the solar neutrino oscillation and parameter determination. – Neutrinos from SN1987A by KAM, and a large statistical observation of galactic supernova is expected in SK. – Atmospheric neutrino anomaly in KAM, and evide ...
A search for ultra-high-energy gamma rays at the South Pole
... an Austrian physicist, Victor Hess, discovered that the outer layers of the Earth's atmosphere are continuously being bombarded by a rain of charged particles called cosmic rays. In yet another of many attempts which have been made in the ensuing years to pin down the origin of this important compon ...
... an Austrian physicist, Victor Hess, discovered that the outer layers of the Earth's atmosphere are continuously being bombarded by a rain of charged particles called cosmic rays. In yet another of many attempts which have been made in the ensuing years to pin down the origin of this important compon ...
form b - University of Iowa Astrophysics
... 9. Galaxy A has a recessional velocity of 2500 km/s and Galaxy B has a recessional velocity of 5000 km/s. What can you say about the two galaxies? (a) Galaxy A is twice as luminous as Galaxy B. (b) Galaxy B is located twice as far away as Galaxy A. (c) Galaxy A’s spectral lines will be more strongly ...
... 9. Galaxy A has a recessional velocity of 2500 km/s and Galaxy B has a recessional velocity of 5000 km/s. What can you say about the two galaxies? (a) Galaxy A is twice as luminous as Galaxy B. (b) Galaxy B is located twice as far away as Galaxy A. (c) Galaxy A’s spectral lines will be more strongly ...
The Age and Progenitor Mass of Sirius B
... is incomplete. At low He abundances The Y43He dependence of the triple α reaction favors the 12 C(α, γ)16 O reaction over triple α. More massive cores with higher entropy favor the production of 16 O over 12 C. Convective He burning cores also tend to grow at low Y4 He due to increased opacity. This ...
... is incomplete. At low He abundances The Y43He dependence of the triple α reaction favors the 12 C(α, γ)16 O reaction over triple α. More massive cores with higher entropy favor the production of 16 O over 12 C. Convective He burning cores also tend to grow at low Y4 He due to increased opacity. This ...
Document
... This process, however, takes place against the will, so to speak, of the elementary units involved. In stars, it is heat that overcomes the repulsive tendency of individual atoms and causes them to fuse together. In the case of human societies, it is warfare. In each case, a strong force was require ...
... This process, however, takes place against the will, so to speak, of the elementary units involved. In stars, it is heat that overcomes the repulsive tendency of individual atoms and causes them to fuse together. In the case of human societies, it is warfare. In each case, a strong force was require ...
Fluorine abundances in dwarf stars of the solar neighbourhood⋆
... of F/O exclude AGB synthesis as the dominant source of fluorine in their targeted stellar populations. In particular, the targeted stars in ω Cen did not have enhanced F abundances, despite their large s-process abundance values. In addition, they claimed a qualitative agreement with what is expecte ...
... of F/O exclude AGB synthesis as the dominant source of fluorine in their targeted stellar populations. In particular, the targeted stars in ω Cen did not have enhanced F abundances, despite their large s-process abundance values. In addition, they claimed a qualitative agreement with what is expecte ...
N-Body Simulations of Star Clusters with IMBH
... Disruption of Stars by the IMBH Most stars disrupted by the IMBH are main-sequence stars and giants. Disruption of neutron stars are rare. During the simulations, no black holes merged with the IMBH. Stars disrupted by the IMBH move on very elongated orbits, so the fate of the ...
... Disruption of Stars by the IMBH Most stars disrupted by the IMBH are main-sequence stars and giants. Disruption of neutron stars are rare. During the simulations, no black holes merged with the IMBH. Stars disrupted by the IMBH move on very elongated orbits, so the fate of the ...
P-nuclei
p-Nuclei (p stands for proton-rich) are certain proton-rich, naturally occurring isotopes of some elements between selenium and mercury which cannot be produced in either s- or r-process.