A beginner's star-book; an easy guide to the stars and to the astronomical uses of the opera-glass, the field-glass and the telescope (1912) (14592347668)

Identifier: beginnersstarboo00murp (find matches)
Title: A beginner's star-book; an easy guide to the stars and to the astronomical uses of the opera-glass, the field-glass and the telescope
Year: 1912 (1910s)
Authors: Murphy, Edgar Gardner, 1869-1913
Subjects: Astronomy
Publisher: New York, London, G.P. Putnam's Sons
Contributing Library: Wellesley College Library
Digitizing Sponsor: Boston Library Consortium Member Libraries



Text Appearing Before Image:
ght. To use an imperfect illustration afforded by other conditions, we maysay that a nebula looks as though it might be a tiny isolated patch of the Milky Way, butin its structure and composition it is gaseous. Sometimes this filmy mass is oval, some-times quite irregular, in form; sometimes it will seem to throw out wisps and streamersof efftdgence, or, again, as shown in the illustration on p. 8, it will seem to us like thelong and shelving undulations of a thin cataract of light, as it slips from star to star in itsshining fall through space. Some of the most remarkable nebulse are spiral in form, and their luminous gases seemcharged with star-like condensations, though no telescope—however great—has everresolved these points of condensation into true stars. Some astronomers regard the 20 a Beoinners Star^Book nebulffi as stars in process of formation, others regard them as stars in process of dis-integration. In certain cases the nebulge seem to be involved in a vast whirlpool
Text Appearing After Image:
THE GREAT NEBULA IN ANDROMEDA, MESSIER 31 From a photograph taken at the Yerkes Observatory motion, throwing off their streams of light and matter as a whirlpool in a flood seemsto throw off its frothing waters from its centre. But so great is their distance from ^be Stellar Moiib 21 US or so inconceivable their magnitude that we have caught as yet no visual evidenceof change. The nebulse, however, are not brilliant objects in small instruments. They are dis-appointing except to those fortunate enough to command facilities far beyond the rangeof the average purse. And yet it is of interest to get such glimpses of them as we may,even if we may not be able to command an impressive view of them. For even thehighest optical aid can do little more than afford a suggestion of the facts. The longerdiameter of the great nebula of Andromeda is more than 500,000 times the distance whichdivides our Sun from the Earth; p. 118; and light, speeding from end to end of this mass