ASTR 1303 Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+, Exams of Astronomy

Download ASTR 1303 Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+ and more Exams Astronomy in PDF only on Docsity! ASTR 1303 Final Exam 2024-2025. Questions and Correct, Verified Answers. Graded A+ ________ selection was able to create a huge variety of species on Earth over 4 billion years. - ANSNatural A _________ is a large gravitationally bound collection of gases and stars. - ANSgalaxy A galaxy like the Milky Way contains __________ of stars. - ANSbillions A globular cluster that has stars all along the main sequence from blue giants to red dwarfs must be - ANSyoung A group of stars all formed at the same time from the same molecular cloud is called a - ANSstar cluster A high-mass star will eventually explode and blow off its outer layers. This is called a - ANStype II supernova A highly magnetized rapidly rotating neutron star is called a - ANSpulsar A light-year is a measurement of - ANSdistance A low mass star (that is not part of a binary star or multi-star system) will end its life as a - ANSwhite dwarf A particle of light is called a - ANSphoton A star in the Milky Way galaxy is 50 light years from earth. When we look at the star in the night sky, we see the star as it - ANSwas 50 years ago. A star's evolutionary path or life cycle on the HR diagram is determined by the star's - ANSmass According to Special Relativity, as you travel faster your clock - ANSslows down. According to the cosmological principle the universe is homogeneous and isotropic. - ANStrue According to the Cosmological Principle, if you were on a distant planet about the size of Earth in another galaxy and you threw a baseball straight up, the baseball would - ANSgo up and then come straight down. According to the general theory of relativity, you cannot tell the difference between being on earth in a gravitational field or being in a spaceship that is moving at constant - ANSacceleration According to the special theory of relativity, you cannot tell the difference between being in a spaceship at rest or being in a spaceship moving at constant - ANSvelocity After a high-mass star blows off its outer layers, the remaining core will become a - ANSneutron star After a hypothesis is tested for a period of time to satisfy scientists without being proved false, it will become a - ANStheory After the helium flash, a low mass star becomes more luminous as it enters the - ANSAGB branch All of your friends like astronomy. Therefore, all people your age like astronomy. This is a type of - ANSlogical fallacy. All spiral galaxies are _________ galaxies. - ANSgiant All stars on the main sequence have the same ________ as our sun. - ANSradius Galaxies are classified according to their - ANSshape Galaxies far away from the Milky Way are moving away _________ galaxies close to the Milky Way. - ANSfaster than Globular clusters contain ______________ of stars. - ANSmillions Gravity is an ________ force between two objects with mass, acting along the line between them. - ANSattractive Heavy elements are created and ejected into interstellar medium by - ANStype 2 supernova Highly energetic, violent bursts and eruptions from the surface of the sun are called - ANScoronal mass ejections How many galaxies are there in the universe? - ANS200 billion How many stars are in the Milky Way galaxy? - ANS200 billion How old is the universe? - ANS13.7 billion years Hydrogen atoms are combined in the core of the sun in the fusion process. What do the hydrogen atoms form? - ANShelium atoms If an astronomer observes a star that is moving toward us, the light of the star is shifted blue. This effect is called - ANSDoppler Shift If an astronomer wants to have a larger image, his telescope should have a larger - ANSfocal length If an astronomer wants to see farther into the universe, his telescope should have a larger - ANSaperture If the mass of a neutron star is more than 3 times the mass of the sun, it will collapse and form a - ANSblack hole If you were able to stand at the center of the earth, the total gravitational forces on you would be - ANSzero In a spiral galaxy, the youngest stars are located in the - ANSouter thin part of the disk In astronomy, homogeneity means that the universe is the same - ANSin all locations In astronomy, isotropy means that the universe is the same - ANSin all directions In his General Theory of Relativity, Einstein revised our understanding of - ANSgravity In his Special Theory of Relativity, ________ proved that Newton was only correct at low velocities (much less than the speed of light). - ANSEinstein In order for the earth centered model of the universe to be true, some of the planets had to move backwards in orbit from time to time. This type of motion is called - ANSretrograde motion In the convection zone, the material (plasma) of the star - ANSswirls and mixes Interstellar extinction is when interstellar dust blocks what kind of light from stars and galaxies? - ANSvisible It is believed that ___________ probably exist at the centers of all galaxies. - ANSsupermassive black holes It is believed that dark matter is most likely a new type of matter called - ANSWIMPs It is believed that dark matter makes up approximately _____ of a galaxy. - ANS95% It is believed that the spiral arms of a spiral galaxy do not wind up tight into the center because of - ANSspiral density waves Kepler's first law says that the planet orbits are in the shape of - ANSellipses Kepler's second law is called the Law of Equal Areas. The consequence of this law is that a planet, while in its orbit around the sun, must move ___________ when it is closer to the sun and __________ when it is farther away from the sun. - ANSfaster / slower Kepler's third law is related to the formula P2/A3=1. This means that a planet far away from the sun will take _______ time to revolve around the sun than a planet closer to the sun. - ANSa longer Life arose mostly from a primordial soup of ________ molecules. - ANSorganic Modern astronomy is the study of - ANSstars, planets, and galaxies Molecular-cloud cores collapse under their own gravity forming - ANSprotostars Newton's first law of motion says that an object at constant velocity will remain at constant velocity unless acted upon by a - ANSforce Newton's second law of motion says that a force applied to a mass will cause the mass to - ANSaccelerate Newton's third law of motion says that for every force, there is an equal and opposite - ANSforce On the Hubble tuning fork, an E0 galaxy is what shape? - ANSsphere Sunspots are caused by disturbances in - ANSmagnetic fields Sunspots are relatively cooler areas on the photosphere that appear - ANSblack Terrestrial life on Earth is based on which element? - ANScarbon The amplitude of an electromagnetic wave is the _______ of the wave. - ANSheight The autumnal equinox occurs in - ANSfall The best way we have to obtain knowledge about distant objects in the universe is to observe - ANSlight The Big Bang occurred 13.7 __________ years ago. - ANSbillion The center of a star is called the - ANScore The closest elliptical galaxy to the Milky Way galaxy is called - ANSSagittarius The closest spiral galaxy to the Milky Way galaxy is called - ANSAndromeda The core of a high-mass star will cause fusion of much larger elements than what is possible in a low- mass star. This is possible because the high-mass star has greater - ANSgravitational forces The core of a low-mass star has a hydrogen to helium content described by the graphs below. The core of a high-mass star has a hydrogen to helium content described by the graphs to the left. What effect in a high-mass star causes the hydrogen to helium content to be mixed evenly near the center of the core. - ANSconvection The core of very low mass stars do not have enough energy to start hydrogen fusion. What are these stars called? - ANSbrown dwarfs The density of interstellar medium is about (FOR REFERENCE: cm3 = 1 centimeter cubed // m3 = 1 meter cubed) - ANS1 cm3 (sugar cube) The detection of the cosmological microwave background radiation, identifying that galaxies are all traveling away from each other, and the concentration of He abundance matching calculations is evidence of the - ANSbig bang The distance to distant galaxies is determined by the brightness and luminosity of _________ in distant galaxies. - ANStype 1a supernova The distance to nearby galaxies is determined by the brightness and luminosity of _________ in nearby galaxies. - ANSvariable stars (cepheids) The Drake Equation was used to estimate of the number of civilizations in the Milky Way galaxy. Based on the number of civilizations estimated to be in the Milky Way galaxy and the size of the Milky Way galaxy, a civilization could be as close as ________ light years away. - ANS40-50 The Drake Equation was used to estimate the number of civilizations in the Milky Way galaxy. It is estimated that _________ advanced civilizations could be in the Milky Way galaxy. - ANS40 million The Earth's axis is tilted approximately 23.5°. The Earth revolves around the Sun. These two facts are responsible for - ANSseasons The energy in the core that causes hydrogen fusion to occur comes from - ANSgravity The farther away two objects with mass are from each other, the _______ the gravitational force between the two objects. - ANSweaker The first scientist to observe the sky with a telescope was - ANSGalileo The general theory of relativity predicts that large massive bodies such as moons, planets, and stars will distort (or curve) - ANSspace-time. The General Theory of Relativity states that space-time is ________ close to massive bodies such as stars and planets. - ANScurved The habitable zone of a planet is an orbital range where water can exist in which form? - ANSliquid The Kepler telescope was used to identify exoplanets. - ANSTrue The mass (M) of a high-mass star is - ANSM > 8 Mʘ The mass (M) of a low-mass star is - ANSM < 3 Mʘ The mass (M) of an intermediate-mass star is - ANS3 Mʘ < M < 8 Mʘ The material in interstellar medium concentrates in some areas to form relatively dense - ANSinterstellar clouds The Milky Way Galaxy (our galaxy) is within a group of galaxies called the Local Group. The Local Group is a group of galaxies within a larger cluster of galaxies called the - ANSVirgo Supercluster The Milky Way galaxy is ___________ galaxy. - ANSa barred The Milky Way galaxy is in a group of galaxies which includes three giant galaxies. The group is called the - ANSLocal Group We can tell that interstellar extinction occurs because __________ light from stars and galaxies passes through interstellar dust. - ANSinfrared What do molecular clouds look like when observed by astronomers? - ANSdark black clouds What is responsible for the days and nights on Earth? - ANSEarth's rotation What is the composition of interstellar medium? - ANSgas and dust What is the hottest region of the sun? - ANScore What is the largest element that will form in the core of a high-mass star by the fusion processes in the core? - ANSiron What is the most dense region of the sun? - ANScore What is the study of the possibility of life in the universe other than that on Earth? - ANSAstrobiology What particle is capable of traveling from the core of the sun to earth because it has very weak interactions with matter? - ANSneutrino When a high-mass star leaves the main sequence, it increases and decreases in size very rapidly. This type of star is called a - ANSpulsating variable star When a hypothesis is proven to be false, scientists must - ANSchange the hypothesis When a low-mass star immediately leaves the main sequence it becomes a - ANSred giant When a low-mass star is at the top of the AGB branch it becomes so large that the gravitational forces within the star are not strong enough to hold onto the outer layers of the star. When the outer layers are ejected into space, they create a - ANSplanetary nebula When a red giant's mass is transferred to a white dwarf in a binary star system and the white dwarf's mass becomes greater than 1.4 M¤ the star will become a - ANStype 1a supernova When a red giant's mass is transferred to a white dwarf in a binary star system and the white dwarf's mass remains less than 1.4 M¤ the star will become a - ANSnova When an electron moves from a high energy state to a lower energy state it will emit - ANSa photon When light moves from air to water the light bends. This is called - ANSrefraction When stars are formed they become main sequence stars. When in the main sequence, stars burn hydrogen into - ANShelium When the core of a red giant becomes hot enough, the fusion of helium begins in the core and there is a helium flash. When this happens, the fusion process turns helium into - ANScarbon When the universe was several thousand years old, the temperature of the universe cooled enough so that protons and electrons formed neutral hydrogen atoms. This event is called - ANSrecombination. When two gravitational objects get too close to each other (within the Roche limits), the tidal forces can cause one or both of the objects to become - ANSunstable When we observe very far away distant galaxies, we are viewing them as they - ANSwere many years ago. Which of the following was produced by the star with the largest mass? - ANSblack hole Which spectral type of star represents the hottest stars. - ANSO5 Which type of telescope uses mirrors? - ANSreflecting Which type of telescope uses two lenses? - ANSrefracting You are moving toward a stationary observer in your spaceship at 0.5c while shining a light toward the stationary observer. At what speed does the stationary observer measure the light from your spaceship? (NOTE: c=speed of light) 0.5c - ANSc You are traveling at 0.8c in your spaceship relative to a stationary observer. The stationary observer measures your length to be __________ you measure your length. (NOTE: c=speed of light) the same as - ANSshorter than You are traveling at 0.8c in your spaceship relative to a stationary observer. Your clock is ___________ the clock of the stationary observer. (NOTE: c=speed of light) - ANSslower than