Distance
... • How much does the apparent brightness of stars we see in the sky vary? Why? • Stars have different colors? So is the amount of light at different wavelengths the same? • Can we tell the difference between a very luminous star that is far away and in intrinsically low luminosity star that is ...
... • How much does the apparent brightness of stars we see in the sky vary? Why? • Stars have different colors? So is the amount of light at different wavelengths the same? • Can we tell the difference between a very luminous star that is far away and in intrinsically low luminosity star that is ...
Here
... radiation as it lands on the stellar surface. Despite the approximations entering our derivation, Lrad is very nearly equal to Lacc throughout the main accretion phase, regardless of the detailed time dependence of Ṁ . Moreover, this equality holds even if the gas first strikes a circumstellar disk ...
... radiation as it lands on the stellar surface. Despite the approximations entering our derivation, Lrad is very nearly equal to Lacc throughout the main accretion phase, regardless of the detailed time dependence of Ṁ . Moreover, this equality holds even if the gas first strikes a circumstellar disk ...
PHYSICS – Astrophysics Section I
... of the Moon. Galileo saw that the Moon was not perfect and unchanging as was the prevailing Aristotelian view, but in fact had a very rough surface. He observed the “seas” and mountains on the surface of the Moon as well as craters. These observations blatantly contradicted the Church’s Aristotelian ...
... of the Moon. Galileo saw that the Moon was not perfect and unchanging as was the prevailing Aristotelian view, but in fact had a very rough surface. He observed the “seas” and mountains on the surface of the Moon as well as craters. These observations blatantly contradicted the Church’s Aristotelian ...
James`s 5-Page Final Exam Review
... able to derive Kepler’s Third Law. Below are three variants of the law that are equally valid: a. Kepler’s Original Third Law: i. What units do you use for P and a? ii. When is this equation applicable? b. Intermediate Kepler’s Third Law: i. What units do you use for P and a? ii. When is this equati ...
... able to derive Kepler’s Third Law. Below are three variants of the law that are equally valid: a. Kepler’s Original Third Law: i. What units do you use for P and a? ii. When is this equation applicable? b. Intermediate Kepler’s Third Law: i. What units do you use for P and a? ii. When is this equati ...
Photographs of a Star Cluster Spectra of a Star Cluster
... emitting light is moving towards you or away from you. – An object moving “side to side” or perpendicular, relative to your line of sight, will not experience a Doppler Effect. ...
... emitting light is moving towards you or away from you. – An object moving “side to side” or perpendicular, relative to your line of sight, will not experience a Doppler Effect. ...
Slides from Dr. Frank`s Lecture17
... The following processes are inevitable in a binary: 1) The binary separation decreases because of gravitational radiation and other angular momentum losses. 2) The component stars will evolve and change size (for example becoming a red giant) Conclusion: Long period (wide) binaries may never become ...
... The following processes are inevitable in a binary: 1) The binary separation decreases because of gravitational radiation and other angular momentum losses. 2) The component stars will evolve and change size (for example becoming a red giant) Conclusion: Long period (wide) binaries may never become ...
Letot STELLAR EVOLUTION By Kyle Letot Grade Level: 6
... star. Using this balloon, I will explain how gravity is holding the stars in place, just as the elastic covering of rubber on the balloon is holding the air in. (I will include that stars do NOT have a membrane such as the balloon, rather the balloon has visual similarities that students can see and ...
... star. Using this balloon, I will explain how gravity is holding the stars in place, just as the elastic covering of rubber on the balloon is holding the air in. (I will include that stars do NOT have a membrane such as the balloon, rather the balloon has visual similarities that students can see and ...
LISTENING FOR THE HUM OF NEUTRON STARS IN THE CENTER
... of its lifetime. This explosion is extremely luminous: for a few weeks the supernova can outshine an entire galaxy and radiate as much energy as the Sun might radiate over its full lifetime. Most of the material of the star is expelled and what remains is an extremely dense and compact object. Conti ...
... of its lifetime. This explosion is extremely luminous: for a few weeks the supernova can outshine an entire galaxy and radiate as much energy as the Sun might radiate over its full lifetime. Most of the material of the star is expelled and what remains is an extremely dense and compact object. Conti ...
Lecture Eight (Powerpoint format) - Flash
... Molecules in Space Instead, astronomers found that molecules were very common in interstellar space -- particularly CO and NH3. The most common molecule in interstellar space -- H2 -- doesn’t emit this type of radio emission and so is nearly invisible. CO Map of Horsehead Nebula (BIMA/M. Pound) ...
... Molecules in Space Instead, astronomers found that molecules were very common in interstellar space -- particularly CO and NH3. The most common molecule in interstellar space -- H2 -- doesn’t emit this type of radio emission and so is nearly invisible. CO Map of Horsehead Nebula (BIMA/M. Pound) ...
1. The gravitational force is the fundamental force that exists
... A) Because of electrostatic repulsion, it is hard to get nuclei close enough for the strong force to take over and fuse them. Heat makes the nuclei move faster, which permits them to get closer. B ) We just went over this. Using thermal energy to start the process would violate the principle of ener ...
... A) Because of electrostatic repulsion, it is hard to get nuclei close enough for the strong force to take over and fuse them. Heat makes the nuclei move faster, which permits them to get closer. B ) We just went over this. Using thermal energy to start the process would violate the principle of ener ...
Fulltext PDF - Indian Academy of Sciences
... magnitude of + S. Thus the determination of absolute magnitude demands the precise knowledge of distance. The colour of stars may also be quantitatively measured by a similar method. Filters with established colour transmission characteristics are standardized and the starlight is measured through t ...
... magnitude of + S. Thus the determination of absolute magnitude demands the precise knowledge of distance. The colour of stars may also be quantitatively measured by a similar method. Filters with established colour transmission characteristics are standardized and the starlight is measured through t ...
Activity 1: The Scientific Method
... 1) Start by becoming aware of your own biases. Do you believe any of the data is correlated? If so how? Relationship Example: radial motion of the stars and temperature Should state relationships that you believe might exist ...
... 1) Start by becoming aware of your own biases. Do you believe any of the data is correlated? If so how? Relationship Example: radial motion of the stars and temperature Should state relationships that you believe might exist ...
Herbig Ae/Be Stars
... starting point for for T Tauri stars depends on factors such as how much thermal energy is added during protostellar accretion + The youngest low mass stars are observed near the birthline, but a definitive observational test does not yet exist + D-burning is insignificant for more massive stars (M ...
... starting point for for T Tauri stars depends on factors such as how much thermal energy is added during protostellar accretion + The youngest low mass stars are observed near the birthline, but a definitive observational test does not yet exist + D-burning is insignificant for more massive stars (M ...
The Interstellar Medium
... remain within it for another 10,000 to 20,000 years. The cloud, which is inside the Local Bubble, has a temperature of 7000° K. Its density is about 0.25 atoms per cubic centimeter, is greater than the Local Bubble, and it is much cooler. The cloud is flowing outwards from the ScorpiusCentaurus Asso ...
... remain within it for another 10,000 to 20,000 years. The cloud, which is inside the Local Bubble, has a temperature of 7000° K. Its density is about 0.25 atoms per cubic centimeter, is greater than the Local Bubble, and it is much cooler. The cloud is flowing outwards from the ScorpiusCentaurus Asso ...
Classifying the Spectra of Stars:
... presence of spectral features due to absorption. The amount of this energy deficit is proportional to the approximate triangular area of the line. Now we convert this triangular area to a rectangle with the height of actual continuum. The width of this rectangle is the equivalent width and is measur ...
... presence of spectral features due to absorption. The amount of this energy deficit is proportional to the approximate triangular area of the line. Now we convert this triangular area to a rectangle with the height of actual continuum. The width of this rectangle is the equivalent width and is measur ...
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.