Sharpless, Isaac, 1848-1920, Philips, G. M. (George Morris), 1851-1920, joint author · Philadelphia, J.B. Lippincott company · leaf 260
goes through itschanges in a period of seventy years: from a star in-visible to the naked eye it increases almost to thebrightness of Sirius. Its increase is not uniform, butnumerous small fluctuations may be noticed along itscourse. The curved line of Fig. 60 shows its changes.The horizontal lines… … Fig. 60. There are about one hundred and fifty known varia-bles. The following table gives the stars in which thevariations may be most easily distinguished. Thoseof the fifth magnitude and over can be seen and studiedby the eye, for those from the fifth to the seventh mag-nitude an opera-glass may…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
