Fourteen Weeks in Descriptive Astronomy |
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Page 53
... penumbra , and vice versa . The umbra itself has generally a dense black centre , called the nucleus . Besides Fig . 6 . SUN SPOTS . this , the umbra is sometimes divided by luminous bridges . The spots are in motion . They change from ...
... penumbra , and vice versa . The umbra itself has generally a dense black centre , called the nucleus . Besides Fig . 6 . SUN SPOTS . this , the umbra is sometimes divided by luminous bridges . The spots are in motion . They change from ...
Page 59
... sun , which have been taken in large numbers of late at Kew Observatory . Comparative brightness of spots and sun . — If we represent the ordinary brightness of the sun by 1,000 , then that of the penumbra would be 469 THE SUN . 59.
... sun , which have been taken in large numbers of late at Kew Observatory . Comparative brightness of spots and sun . — If we represent the ordinary brightness of the sun by 1,000 , then that of the penumbra would be 469 THE SUN . 59.
Page 60
Joel Dorman Steele. 1,000 , then that of the penumbra would be 469 , and that of the nucleus 7. There may be much light and heat radiated by a spot , which seems totally black as compared with the sun : we remember that when we look ...
Joel Dorman Steele. 1,000 , then that of the penumbra would be 469 , and that of the nucleus 7. There may be much light and heat radiated by a spot , which seems totally black as compared with the sun : we remember that when we look ...
Page 61
... , " which appears to slowly increase and as- sume the blackness of an umbra , after which the penumbra begins to appear . PHYSICAL CONSTITUTION OF THE SUN . - Of the consti- tution of the sun , and consequent cause of the. THE SUN . 61.
... , " which appears to slowly increase and as- sume the blackness of an umbra , after which the penumbra begins to appear . PHYSICAL CONSTITUTION OF THE SUN . - Of the consti- tution of the sun , and consequent cause of the. THE SUN . 61.
Page 62
... penumbra . This explains a black spot with its penumbra . Sometimes the opening in the photo- sphere may be smaller than that in the inner or cloudy atmosphere ; in that case there will be a black spot without a penumbra . It will be ...
... penumbra . This explains a black spot with its penumbra . Sometimes the opening in the photo- sphere may be smaller than that in the inner or cloudy atmosphere ; in that case there will be a black spot without a penumbra . It will be ...
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Common terms and phrases
ancients Andromeda angle aphelion appear Aries astronomers atmosphere axis Boötes bright brilliant Canis Minor Capricornus Cassiopeia cause Celestial Sphere centre Cepheus circle color comet conjunction constellation Cor Caroli dark density Describe diameter disk earth east ecliptic equal equator equinoctial figure fixed stars full moon globe heat heavenly bodies heavens Hercules Herschel horizon inclined inferior conjunction inferior planet Jupiter latitude length light luminous lunar Lyra magnitude Mars mean distance Mercury meridian meteors miles moon's motion move naked eye nearly nebula Neptune night node north pole Orion parallax pass path penumbra perihelion Perseus Pisces polar Polaris precession rays revolve ring rising Saturn seasons seen shine side sidereal sidereal day solar day solar system solstice space spots summer sun's surface synodic revolution tance Taurus telescope theory tion Uranus Ursa Major Ursa Minor varies velocity Venus vernal equinox visible winter Zodiac