Physics 127 Descriptive Astronomy Homework #20 Key
... Hubble was able to detect Cepheid variable stars within that “Nebula.” Then by observing their light curves and using the known period- luminosity relation for Cepheids, he obtained and compared the absolute magnitudes of these Cepheids with his observed apparent magnitudes, yielding a distance for ...
... Hubble was able to detect Cepheid variable stars within that “Nebula.” Then by observing their light curves and using the known period- luminosity relation for Cepheids, he obtained and compared the absolute magnitudes of these Cepheids with his observed apparent magnitudes, yielding a distance for ...
1 Correct responses in BOLDFACE. 1. Henrietta Leavitt`s period
... a. at the end the electrons in the atoms have gone to lower energy levels and given off the energy they lost b. the atoms join together into bigger molecules, and the molecular binding energy is released c. the fusion products weigh a little less than the input materials, and the mass that is lost a ...
... a. at the end the electrons in the atoms have gone to lower energy levels and given off the energy they lost b. the atoms join together into bigger molecules, and the molecular binding energy is released c. the fusion products weigh a little less than the input materials, and the mass that is lost a ...
©M. Rieke 1 Correct responses in BOLDFACE. 1. Why did
... d. the continents would still be there, but the mountains would be much lower e. the oceans would silt up 38. If we have a container of hydrogen gas sitting in a laboratory on Earth, why doesn't it turn into helium? ...
... d. the continents would still be there, but the mountains would be much lower e. the oceans would silt up 38. If we have a container of hydrogen gas sitting in a laboratory on Earth, why doesn't it turn into helium? ...
1 - Alice Pevyhouse
... 4. The scientist who first made astronomical observations that showed the validity of the heliocentric model of the solar system was 5. The most important observation made to validate(show it was true) the heliocentric model was: ...
... 4. The scientist who first made astronomical observations that showed the validity of the heliocentric model of the solar system was 5. The most important observation made to validate(show it was true) the heliocentric model was: ...
Astronomy1: Midterm 3 Practice Exam
... e. radio 7. When a low density gas is heated up and only a few wavelengths are bright, it is called a/an: a. emission line spectrum b. absorption line spectrum c. continuous spectrum 8. What type of radiation does our Sun mostly produce? a. infrared b. gamma rays c. white light d. ultraviolet e. rad ...
... e. radio 7. When a low density gas is heated up and only a few wavelengths are bright, it is called a/an: a. emission line spectrum b. absorption line spectrum c. continuous spectrum 8. What type of radiation does our Sun mostly produce? a. infrared b. gamma rays c. white light d. ultraviolet e. rad ...
PHYS 175 (2014) Final Examination Name: ___SOLUTION_____
... 29. Which of the following statements about the cosmic background radiation is incorrect? ...
... 29. Which of the following statements about the cosmic background radiation is incorrect? ...
Study Guide for Stars and the Universe Test
... Extra Credit Questions for the Stars and the Universe Test 1. What types of radiation make up the electromagnetic spectrum? 2. Define the three types of spectra. 3. How do scientists determine the elements present in a star. 4. How can scientists determine whether a star is moving toward or away fro ...
... Extra Credit Questions for the Stars and the Universe Test 1. What types of radiation make up the electromagnetic spectrum? 2. Define the three types of spectra. 3. How do scientists determine the elements present in a star. 4. How can scientists determine whether a star is moving toward or away fro ...
Study Guide: Unit 1, The Universe and its Stars, HS
... 12) HS-ESS1-1 The name applied to concentrations of interstellar matter that glow when it is close to very hot stars is ________. A) granules B) prominences C) nebulas D) quasars E) plages 13) HS-ESS1-1 As _____________ shrinks, gravitational energy is converted into energy of motion, or heat energy ...
... 12) HS-ESS1-1 The name applied to concentrations of interstellar matter that glow when it is close to very hot stars is ________. A) granules B) prominences C) nebulas D) quasars E) plages 13) HS-ESS1-1 As _____________ shrinks, gravitational energy is converted into energy of motion, or heat energy ...
MULTIPLE CHOICE. Choose the one alternative that best
... 2) Studies of sunquakes, or helioseismology, have revealed that A) ʺsunquakesʺ are caused by similar processes that create earthquakes on Earth. B) the Sun generates energy by nuclear fusion. C) our mathematical models of the solar interior are fairly accurate. D) the Sun vibrates only on the surfac ...
... 2) Studies of sunquakes, or helioseismology, have revealed that A) ʺsunquakesʺ are caused by similar processes that create earthquakes on Earth. B) the Sun generates energy by nuclear fusion. C) our mathematical models of the solar interior are fairly accurate. D) the Sun vibrates only on the surfac ...
INV 12B MOTION WITH CHANGING SPEED DRY LAB DATA
... 3. How does the sun compare to the other stars on the main sequence? (Hint: The sun’s color is …..What part of the main sequence is it in – upper left, lower left, etc.?) ...
... 3. How does the sun compare to the other stars on the main sequence? (Hint: The sun’s color is …..What part of the main sequence is it in – upper left, lower left, etc.?) ...
Quiz Solution: 1 April 2013 What does it mean when an astronomer
... Quiz Solution: 1 April 2013 What does it mean when an astronomer says that a star "moves" from one place to another on an H-R Diagram? Can you provide an example of this? As stars evolve and change structure, their radii and temperatures also change. Since a star's luminosity is dependent on both te ...
... Quiz Solution: 1 April 2013 What does it mean when an astronomer says that a star "moves" from one place to another on an H-R Diagram? Can you provide an example of this? As stars evolve and change structure, their radii and temperatures also change. Since a star's luminosity is dependent on both te ...
15 Stellar Structure
... The Source of Stellar Energy Recall from our discussion of the Sun: Stars produce energy by nuclear fusion of hydrogen into helium. ...
... The Source of Stellar Energy Recall from our discussion of the Sun: Stars produce energy by nuclear fusion of hydrogen into helium. ...
Test#3
... 1. A measurement of the parallax of a star allows us directly to determine the star's a) rotation rate, b) temperature, c) distance, d) age 2. How much brighter would a star be if an observer moved from 3 to 1 parsec from the star? a) 3 times, b) 9 times, c) 27 times, d) 81 times 3. The difference b ...
... 1. A measurement of the parallax of a star allows us directly to determine the star's a) rotation rate, b) temperature, c) distance, d) age 2. How much brighter would a star be if an observer moved from 3 to 1 parsec from the star? a) 3 times, b) 9 times, c) 27 times, d) 81 times 3. The difference b ...
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.