The Swansong of Stars Orbiting Massive Black Holes
... The signal is expected to be weak. To detect it, it is necessary to know in advance the shape of the wave trains, and to do that, it is necessary to know the eccentricity of the inspiral orbits. High eccentricity can change the nature of the signal drastically. The eccentricity also determines how m ...
... The signal is expected to be weak. To detect it, it is necessary to know in advance the shape of the wave trains, and to do that, it is necessary to know the eccentricity of the inspiral orbits. High eccentricity can change the nature of the signal drastically. The eccentricity also determines how m ...
Chapter 10. Stellar Spectra
... in the atmospheres of almost all stars. Note that Helium also has two ionization states. In its neutral state (HeI) it has 2 electrons. It can lose one of those, in which case it becomes HeII, or singly ionized Helium. We see lines of HeI in B stars, which are hotter than A stars, but not as hot as ...
... in the atmospheres of almost all stars. Note that Helium also has two ionization states. In its neutral state (HeI) it has 2 electrons. It can lose one of those, in which case it becomes HeII, or singly ionized Helium. We see lines of HeI in B stars, which are hotter than A stars, but not as hot as ...
Answers
... Hint: Consider the different stages these two stars will go through during their lifetime, and the properties of the final stages. Both stars will become supergiants after leaving the Main Sequence. When the core of the star collapses, both stars will explode as a Supernova. The 40 Msun star will re ...
... Hint: Consider the different stages these two stars will go through during their lifetime, and the properties of the final stages. Both stars will become supergiants after leaving the Main Sequence. When the core of the star collapses, both stars will explode as a Supernova. The 40 Msun star will re ...
Galaxy Powerpoint
... E. Small & Medium Stars: (low mass stars) 2. Red Giant Phase- Beginning stage of death for small & medium size stars. a.) The fusion and gravity of a star becomes unbalanced do to hydrogen running out. b.) This makes the star collapse in on it self. c.) Another round of fusion is triggered. This ti ...
... E. Small & Medium Stars: (low mass stars) 2. Red Giant Phase- Beginning stage of death for small & medium size stars. a.) The fusion and gravity of a star becomes unbalanced do to hydrogen running out. b.) This makes the star collapse in on it self. c.) Another round of fusion is triggered. This ti ...
solutions 3
... 4. Pauli Pressure and White Dwarf stars A star like the Sun is essentially a box of hydrogen, held together by gravity. After 10 billion years or so, the core of the star contains enough helium and other fusion products that the fusion processes slow down and the star begins to cool and contract. Ev ...
... 4. Pauli Pressure and White Dwarf stars A star like the Sun is essentially a box of hydrogen, held together by gravity. After 10 billion years or so, the core of the star contains enough helium and other fusion products that the fusion processes slow down and the star begins to cool and contract. Ev ...
Overview: The Sun The outer layers Photosphere: Visible Surface
... Corona or “crown” of the Sun ...
... Corona or “crown” of the Sun ...
Question paper - Unit 5 (6PH05) - January 2012
... property of dark matter is that it A absorbs all electromagnetic-radiation. B cannot be detected. C emits no detectable electromagnetic-radiation. D exerts no gravitational force. (Total for Question 5 = 1 mark) 6 Cosmologists describe the universe as being open, closed or flat. A closed universe is ...
... property of dark matter is that it A absorbs all electromagnetic-radiation. B cannot be detected. C emits no detectable electromagnetic-radiation. D exerts no gravitational force. (Total for Question 5 = 1 mark) 6 Cosmologists describe the universe as being open, closed or flat. A closed universe is ...
T = 5800 K
... A neutral atom consists of a nucleus, made of protons and neutrons, and enough electrons to neutralize the positive charge of the protons. The diameter of the nucleus is about 1 femtometer (1 fm = 10-15m). The “cloud” of electrons, on the other hand, occupies a volume with a diameter of about 0.1 nm ...
... A neutral atom consists of a nucleus, made of protons and neutrons, and enough electrons to neutralize the positive charge of the protons. The diameter of the nucleus is about 1 femtometer (1 fm = 10-15m). The “cloud” of electrons, on the other hand, occupies a volume with a diameter of about 0.1 nm ...
Lecture 9a: More on Star formation and evolution 10/22
... with modest telescope • usually dim red stars • dense with 100,000 stars in 50-300 LY region with less than LY separating stars • no heavy elements. Just Hydrogen and Helium • often outside plane of galaxy Understood as group of old stars formed in early history of the galaxy 3-12 billion years ...
... with modest telescope • usually dim red stars • dense with 100,000 stars in 50-300 LY region with less than LY separating stars • no heavy elements. Just Hydrogen and Helium • often outside plane of galaxy Understood as group of old stars formed in early history of the galaxy 3-12 billion years ...
PHYS 2410 General Astronomy Homework 8
... as the material slows down it converts thermal energy to gravitational potential energy. ...
... as the material slows down it converts thermal energy to gravitational potential energy. ...
Phys133 SAMPLE questions for MidTerm#1
... 12) Which scientists played a major role in overturning the ancient idea of an Earth-centered universe, and about when? A) Newton and Einstein; about 100 years ago B) Aristotle and Copernicus; about 400 years ago C) Aristotle and Plato; about 2,000 years ago D) Copernicus, Kepler, and Galileo; about ...
... 12) Which scientists played a major role in overturning the ancient idea of an Earth-centered universe, and about when? A) Newton and Einstein; about 100 years ago B) Aristotle and Copernicus; about 400 years ago C) Aristotle and Plato; about 2,000 years ago D) Copernicus, Kepler, and Galileo; about ...
Notes_ stars and sun
... • A more practical use for constellations was in farming cultures. • People began to learn that when Orion was fully visible, that winter was coming soon. • The star patterns made it easier for early farming cultures to know when to plant. • Constellations were named from the Greeks. • They are ...
... • A more practical use for constellations was in farming cultures. • People began to learn that when Orion was fully visible, that winter was coming soon. • The star patterns made it easier for early farming cultures to know when to plant. • Constellations were named from the Greeks. • They are ...
Ch 28 Outline
... iron nuclei are formed. After a lifespan of LESS than a billion years, the star swells to more than 100x the diameter of our Sun → becoming a supergiant. The formation of iron nuclei does NOT release energy; instead it ABSORBS energy, so the iron core quickly and suddenly collapses producing a shock ...
... iron nuclei are formed. After a lifespan of LESS than a billion years, the star swells to more than 100x the diameter of our Sun → becoming a supergiant. The formation of iron nuclei does NOT release energy; instead it ABSORBS energy, so the iron core quickly and suddenly collapses producing a shock ...
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.