The Geography of the Heavens, and Class Book of Astronomy; Accompanied by a Celestial Atlas |
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Results 6-10 of 48
Page 48
... changes from a star of the 2d mag- nitude so as to become invisible once in 234 days , or about 7 times in 6 years . Herschel makes its period 331 days , 10 hours , and 19 minutes ; while Hevelius assures us that it once disappeared for ...
... changes from a star of the 2d mag- nitude so as to become invisible once in 234 days , or about 7 times in 6 years . Herschel makes its period 331 days , 10 hours , and 19 minutes ; while Hevelius assures us that it once disappeared for ...
Page 50
... changes recur . The periodical variation of Algol was determined in 1783 , by John Goodricke of York ( Eng . ) to be 2 days , 20 hours , 48 minutes , and 56 seconds . Dr. Herschel attributes the variable appearance of Algol to spots ...
... changes recur . The periodical variation of Algol was determined in 1783 , by John Goodricke of York ( Eng . ) to be 2 days , 20 hours , 48 minutes , and 56 seconds . Dr. Herschel attributes the variable appearance of Algol to spots ...
Page 51
... changes in the lustre of the stars , so satisfactorily , that we certainly need not look out for any other cause . " It is said , that the famous astronomer Lalande , who died at Paris in 1807 , was wont to reinain whole nights , in his ...
... changes in the lustre of the stars , so satisfactorily , that we certainly need not look out for any other cause . " It is said , that the famous astronomer Lalande , who died at Paris in 1807 , was wont to reinain whole nights , in his ...
Page 67
... changes at different periods ; whence it has been conjectured by various astronomers that Pollux must vary from the 1st to the 3d magnitude . But Herschel , who observed these stars for a period of 25 years , ascribes the variation to ...
... changes at different periods ; whence it has been conjectured by various astronomers that Pollux must vary from the 1st to the 3d magnitude . But Herschel , who observed these stars for a period of 25 years , ascribes the variation to ...
Page 72
... changes its position in respect to the seasons . How long is light in coming from Sirius to the earth ? Suppose this star were now to be blotted from the heavens , how long before its twinkling would expire ? How was the rising of ...
... changes its position in respect to the seasons . How long is light in coming from Sirius to the earth ? Suppose this star were now to be blotted from the heavens , how long before its twinkling would expire ? How was the rising of ...
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Common terms and phrases
3d magnitude 4th magnitude ancient angle appear Arcturus Argo Navis Aries astronomers Auriga axis Beta brightest called Cassiopeia celestial centre Cepheus circle cluster colure comet constellation Cor Caroli declination degree Delta Denebola Describe diameter direction distinguished diurnal motion Earth east ecliptic equal equator equinoctial figure fixed stars Gamma globe head heavenly bodies heavens Hercules Herschel horizon Jupiter latitude length Libra light longitude mean distance Mercury meridian millions of miles minutes Moon Moon's motion naked eye nearly nebulæ night node north pole northern hemisphere observed orbit Orion parallax passing perihelion period Perseus phenomena planets Pleiades polar star position principal star represented revolution revolve right ascension rise satellites Saturn seasons seen side sidereal Sirius situated small stars solar system solstice southern spots Sun's supposed surface Taurus telescope tion triangle Ursa Venus vernal equinox Virgo visible whole number Zeta Zodiac