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30 Cards in this Set
- Front
- Back
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Galileos telescopic discoveries of mountains on the moon and spots on the sun were contraversial because the sugested that the sun and moon
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were not perfect spheres
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the force due to gravity depends on
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the mass of each object and the distance betweeen the 2 objects
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hallys comethas an orbital period of 76 yrs what is the average distance of 65 AU what is the approximate orbital period of this object
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524 yrs
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ultravoilet radiation from a star
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will not penetrate earths atmosphere and reach the ground
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long wavelentgh visible light
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will appear red in color to the average to the average human eye
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which electromagnetic radiation has smallest frequency
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radio
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which electromagnetic radiation has lowest energy
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infrared radiation
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increasing the diameter of a telescope
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increases its light gathering power and resolving power
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what is the magnification of a telescope and eyepeice has a focal length of 2.0cm
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100 times
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an atom can be excited
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if it collides with another atom or electron and if it absorbs a photon
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why dont we see hydrogen balmer lines in the spectra of stars with temperatures of 3200k
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these stars are so cool that nearly all of the hydrogen atoms are in the ground state.
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the radiation emitted from a star has a maximim intensity at a wavelength of 300nm. what is the temp of this star?
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10000k
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most of the light we see coming from the sun originates in the
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photosphere
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sunspots are known to be magnetic phenomena because
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the Zeeman effect is observed in sunspots
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which is evidence that convection occurs in the layers just below the sun's photosphere
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the centers of granules are hot and moving away from the center of the sun
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A_____ is belived to occur when energy, stored in a twist in the solar magnetic field above a sunspot, is suddenly released
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solar flare
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absolute visual magnitude is
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the apparent magnitude of a star observed from a distance of 10 pc
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in the H-R diagram 90 percent of all stars are
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on the main sequence
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the _____ of a star is a measure of hte total energy radiated by the star in one second
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luminosity
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an elcipsing binary will
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always be a spectroscopic binary
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which of the following must obey the mass-luminosity relation
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the main sequence stars
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protostars are difficult to observe because
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short,cocoons of stars and gas, radiate infrared
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nuclear reactions in a stars core remain under control so long as
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pressure depends on temp
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interstellar gas clouds may collapse to form stars if they
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encounter a shock wave
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the main sequence has a limit ar the lower end because
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there is a minimum temp for hydrogen fusion
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there is a mass-luminosity realtion because
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stars support their weight by making energy
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the lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about
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0.08M
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absorbtion lines due to the interstellar medium indicate that some components of the interstellar medium are cold and of very low density because
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the lines are extremly narrow
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in ad 1054 chinese atronomers observed the appearence of a new star whose location is now occupied by
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a pulsar, a neutron star, supernova remnant
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an isolated black hole in space would be difficult to detect because
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very little matter would be falling into it
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