History of Astronomy |
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Page 128
... or 63,072 astronomical units ; I astronomical unit a year = 2.94 miles a second ; and the earth's orbital velocity = 18.5 miles a second . motions and parallaxes combined tell us the velocity of the 128 THE PHYSICAL PERIOD.
... or 63,072 astronomical units ; I astronomical unit a year = 2.94 miles a second ; and the earth's orbital velocity = 18.5 miles a second . motions and parallaxes combined tell us the velocity of the 128 THE PHYSICAL PERIOD.
Page 129
... astronomical units a year ; 61 Cygni 37.9 miles a second = 11.2 astronomical units a year . These successes led to renewed zeal , and now the distances of many stars are known more or less accurately . Several of the brightest stars ...
... astronomical units a year ; 61 Cygni 37.9 miles a second = 11.2 astronomical units a year . These successes led to renewed zeal , and now the distances of many stars are known more or less accurately . Several of the brightest stars ...
Page 130
... astronomical units a year . The work of Herschel in this matter has been checked by comparing spectroscopic velocities in the line of sight which , so far as the sun's motion is concerned , would give a maximum rate of approach for ...
... astronomical units a year . The work of Herschel in this matter has been checked by comparing spectroscopic velocities in the line of sight which , so far as the sun's motion is concerned , would give a maximum rate of approach for ...
Page 131
... astronomical units a year . The average proper motion of a first magnitude star has been found to be o " .25 annually , and of a sixth magnitude star o " .04 . But that all bright stars are nearer than all small stars , or that they ...
... astronomical units a year . The average proper motion of a first magnitude star has been found to be o " .25 annually , and of a sixth magnitude star o " .04 . But that all bright stars are nearer than all small stars , or that they ...
Page 132
... astronomical units . On examining these . stereoscopically , some of the stars rise out of the general plane of the stars , and seem to be much nearer . Many of the stars are thus seen to be sus- pended in space at different distances ...
... astronomical units . On examining these . stereoscopically , some of the stars rise out of the general plane of the stars , and seem to be much nearer . Many of the stars are thus seen to be sus- pended in space at different distances ...
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accurate observations Airy astro Astronomer Royal Astronomia Nova astronomical units attraction axis bright calculations Cape Cassini catalogue centre century comet compute Copernicus diameter discovered discovery earth eclipse epicycles equatoreal error excentric explain fact fixed stars Galileo Greenwich Halley heavenly bodies heavens heliometer Hipparchus Huggins hydrogen hypothesis instruments Johann Kepler John Herschel Jupiter Jupiter's Kepler Laplace Lick Observatory light line of apses line of sight lunar Mars mathematical mean distance mean motion measured Mercury meteor method miles a second moon moon's nebulę Newton Observatory orbit parallax perihelion period photographic physical planet planetary pole position predicted proper motion proved Ptolemy R. S. Phil records refractor retrograde retrograde motion revolution revolve round ring rotation round the sun satellites seems showed Sirius solar system spectra spectroscope spectrum spots stellar sun-spots sun's surface supposed tables telescope theory tion Trans Tycho Brahe Uranus velocity Venus Verrier zenith