Astro 7N Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+, Exams of Astronomy

Download Astro 7N Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+ and more Exams Astronomy in PDF only on Docsity! Astro 7N Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+ a 2-solar-mass main sequence stat is at the same distance as a 0.2-solar-mass main sequence star. Which star appears brighter? - ANSthe 2 solar mass main sequence star appears brighter a galaxy has an H-alpha emission line observed at a wavelength 10 percent larger than the rest wavelength of H-alpha. What is the redshift of the galaxy? - ANS0.1 A high-luminosity star - ANSemits more light than a low-luminosity star among these choices, what is the last thing that happens in the history of the universe? - ANSelectrons join with nuclei to make atoms An estimate of the number of communicating/technological civilizations that we expect in our galaxy would be a larger number if - ANSthe average number of planets that could support life for each star were larger an older star cluster - ANShas a main sequence turnoff farther to the right on the H-R diagram fill in the blank in the following chemical reaction that occurs in the sun - ANShydrogen-2 + proton = helium-3 + energy galaxy A appears twice the angular size of galaxy B. Assuming the two galaxies have the same physical size in kiloparsecs, which of the following is true? - ANSGalaxy B is 2 times farther away than galaxy A How do astronomers measure the temperature of stars? - ANSby looking at which absorption lines are present in the star's spectrum how does a star move on the H-R diagram during the period of time it is converting hydrogen to helium in its core - ANSit remains nearly fixed at a certain point on the main sequence and does not move on the H-R diagram how many times bigger is the local group of galaxies in which the milky way resides than the milky way itself - ANSabout 100 times bigger How tiny a spot is the hubble deep field? - ANSThe size of President Roosevelt's eye on a dime held at arm's length if a galaxy had no dark matter, we would observe - ANSthe rotation velocity would decrease with increasing distance like the Keplerian curve in our solar system if a galaxy is moving away from us the wavelength of the light it emits will be - ANSincreased If a red giant appears the same brightness as a red main sequence star, which one is farther away - ANSthe red giant if the entire mass of earth were concentrated in a region the size of a marble, the resulting object would be - ANSa black hole if the sun had twice its mass, then which of these planets would be in its habitable zone - ANSjupiter if they were all formed at the same time, which of the stars in the diagram above will live the longest? - ANSB in the figure above, how would you calculate the fraction of the mass of the gas in the universe that is in the form of helium? - ANStake 4x4 for the mass of helium, and divide 4x4 + 48x1 for the total mass In the inverse square law activity above, what would the wattage of the top lightbulb need to be, such that it appeared as bright as the bottom lightbulb which is a 35-watt bulb? - ANS100 watts In the p-p chain, shown in the above diagram, what particles must be input in order to produce one 4HE nucleus? - ANS6 protons, but 2 of them are returned when the 4 HE is produced