Characteristics of Stars
... • The fusion of Atoms Hydrogen atoms fusing to form Helium releasing Heat, Light and energy • Astronomers use a Spectroscope to determine the composition of a Star ...
... • The fusion of Atoms Hydrogen atoms fusing to form Helium releasing Heat, Light and energy • Astronomers use a Spectroscope to determine the composition of a Star ...
The coolest White Dwarf— older than the age of the universe?
... magnetic field of the present pulsar is some 7.2 × 109 Gauss as compared to the earth’s 0.25–0.65 Gauss. The double flash (see figure 2) is due to the fact that the pulsar’s two beams along magnetic axes are misaligned with the poles of rotation. The earth observer sees a stronger flash from the bea ...
... magnetic field of the present pulsar is some 7.2 × 109 Gauss as compared to the earth’s 0.25–0.65 Gauss. The double flash (see figure 2) is due to the fact that the pulsar’s two beams along magnetic axes are misaligned with the poles of rotation. The earth observer sees a stronger flash from the bea ...
Astronomy HOMEWORK Chapter 12 - 9th Edition 1. Consider a star
... other stages) are the high-mass ones. So “How:” the turnoff point is determined (L and T ). These values are correlated with a lifetime, and that’s the age of the cluster. 16. Why do astronomers believe that most globular clusters are made of old stars? Answer: See the H-R diagram for M55, Fig 12-30 ...
... other stages) are the high-mass ones. So “How:” the turnoff point is determined (L and T ). These values are correlated with a lifetime, and that’s the age of the cluster. 16. Why do astronomers believe that most globular clusters are made of old stars? Answer: See the H-R diagram for M55, Fig 12-30 ...
Solutions to problems
... major spectral types, O, B, A, F, G, K, M. The differences in the spectral type correspond to differences in temperature, with the hottest stars of type O and the coolest type M. The differences in temperature of the stars depends almost entirely on the mass of the star, with the temperature of the ...
... major spectral types, O, B, A, F, G, K, M. The differences in the spectral type correspond to differences in temperature, with the hottest stars of type O and the coolest type M. The differences in temperature of the stars depends almost entirely on the mass of the star, with the temperature of the ...
Which has a hotter temperature, a red star or a blue star? How do
... The moon takes a full month to cycle through all of its phases (29.5 days, really). If the moon is a waining gibbous tonight, what will the phase be 2 weeks from now? Draw the position of the Earth, Moon, and Sun when the moon appears as a waining gibbous from the Earth. What fraction of a full cyc ...
... The moon takes a full month to cycle through all of its phases (29.5 days, really). If the moon is a waining gibbous tonight, what will the phase be 2 weeks from now? Draw the position of the Earth, Moon, and Sun when the moon appears as a waining gibbous from the Earth. What fraction of a full cyc ...
ppt
... ~0.7% of the H mass is converted into energy, releasing 26.71 MeV. E.g. Assume the Sun was originally 100% hydrogen, and converted the central 10% of H into helium. How much energy would it produce in its lifetime? ...
... ~0.7% of the H mass is converted into energy, releasing 26.71 MeV. E.g. Assume the Sun was originally 100% hydrogen, and converted the central 10% of H into helium. How much energy would it produce in its lifetime? ...
Integrative Studies 410 Our Place in the Universe
... • Density and temperature increase towards center • Very hot & dense core produces all the energy by hydrogen nuclear fusion • Energy is released in the form of EM radiation and particles (neutrinos) • Energy transport well understood in physics ...
... • Density and temperature increase towards center • Very hot & dense core produces all the energy by hydrogen nuclear fusion • Energy is released in the form of EM radiation and particles (neutrinos) • Energy transport well understood in physics ...
Stars - Denbigh Baptist Christian School
... 93 million miles (150 million km) Close proximity allows us to study it more easily. Apply knowledge from our star to other stars Composition 70 % hydrogen 28 % helium 2 % trace elements Planets reflect light Sun and other stars produce light Light production is accomplished via nuclear fusion ...
... 93 million miles (150 million km) Close proximity allows us to study it more easily. Apply knowledge from our star to other stars Composition 70 % hydrogen 28 % helium 2 % trace elements Planets reflect light Sun and other stars produce light Light production is accomplished via nuclear fusion ...
Type II supernova
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times, the mass of the Sun (M☉) for this type of explosion. It is distinguished from other types of supernovae by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing increasingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by these fusion reactions are sufficient to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The star fuses increasingly higher mass elements, starting with hydrogen and then helium, progressing up through the periodic table until a core of iron and nickel is produced. Fusion of iron or nickel produces no net energy output, so no further fusion can take place, leaving the nickel-iron core inert. Due to the lack of energy output allowing outward pressure, equilibrium is broken.When the mass of the inert core exceeds the Chandrasekhar limit of about 1.4 M☉, electron degeneracy alone is no longer sufficient to counter gravity and maintain stellar equilibrium. A cataclysmic implosion takes place within seconds, in which the outer core reaches an inward velocity of up to 23% of the speed of light and the inner core reaches temperatures of up to 100 billion kelvin. Neutrons and neutrinos are formed via reversed beta-decay, releasing about 1046 joules (100 foes) in a ten-second burst. The collapse is halted by neutron degeneracy, causing the implosion to rebound and bounce outward. The energy of this expanding shock wave is sufficient to accelerate the surrounding stellar material to escape velocity, forming a supernova explosion, while the shock wave and extremely high temperature and pressure briefly allow for theproduction of elements heavier than iron. Depending on initial size of the star, the remnants of the core form a neutron star or a black hole. Because of the underlying mechanism, the resulting nova is also described as a core-collapse supernova.There exist several categories of Type II supernova explosions, which are categorized based on the resulting light curve—a graph of luminosity versus time—following the explosion. Type II-L supernovae show a steady (linear) decline of the light curve following the explosion, whereas Type II-P display a period of slower decline (a plateau) in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium. As a result, they appear to be lacking in these elements.