Canopus — A Mighty Celestial Furnace 



It is so far away that we see it by the Ught that left it in 

 the 15th century, and it is 139 times bigger than our Sun 



By Scriven Bolton, F. R. A. S., M. B. A. A. 



IF we took up our abode at a distance 

 equal to one of the nearest stars, say 

 Alpha Centauri, long before arriving 

 there our world would be totally invisible, 

 even if we carried with us a powerful 

 telescope. The ratio which it bears to 

 the visible universe of stars is incon- 

 ceivably less than that which a single drop 

 of water bears to all the oceans of the 

 world united. 



The immensity of the stellar universe 

 will never be comprehended by our finite 

 intelligence. Let us, however, contem- 

 plate the intervals of time required for 

 light to bridge the awful gulfs of space 

 around us. Traveling at the rate of at 

 least 188,000 miles per second, light takes 

 four years to reach us from the nearest 

 bright star. Yet the velocity of that 

 light is sufficient to circuit the earth at 

 the equator no less than seven and a half 

 times in a single second. The light from 

 many stars occupies hundreds and even 

 thousands of years in the journey; hence 

 we gaze upon them to-day as they were 

 centuries ago, and if at the present mo- 

 ment they ceased to shine, our senses 

 would remain unnotified of the fact till 

 centuries hence. Further, it has recently 

 been ascertained that stars in the Magel- 

 lanic star cloud are so very distant that 

 their light requires 30,000 years to reach 

 us! A striking witness to the inconceiv- 

 able dimensions of what may be termed 

 a microscopic corner of the heavens was 

 forthcoming in 1901, when the new star 

 Nova Persei suddenly burst forth. The 

 rays of light thus propagated took many 

 months in reaching and finally illuminat- 

 ing the nebulous region situated "locally" 

 one might say. 



The question of the size of different 

 bodies poised in this infinite space is one 

 which frequently arises, and the slumber- 

 ing sense is startled on learning of the 

 existence of spheres hundreds, thousands, 

 millions of times larger than our globe. 

 Situated as we are near the center of the 

 Milky Way, that beautiful soft track of 



light which forms a complete circle of 

 light round the earth, we hold a position 

 in the heavens favorable to an inspection 

 of our neighbors. We are apt to be mis- 

 lead by the assumption that the brightest 

 stars represent those nearest us. As- 

 tronomers have found that distances 

 vary quite irrespectively of brightness, 

 for throughout space we find big and httle 

 stars strewn alike in haphazard fashion. 



How Small Is Our Mighty Sun! 



As in many things common to our- 

 selves, appearances are often decidedly 

 misleading. We might say that our sun 

 is larger than other suns. Careful 

 measurement, however, tells us that our 

 luminary represents just an average sized 

 member of the celestial host. But to 

 say that it attains a diameter of 865,000 

 miles is a bare statement which fails to 

 awaken an adequate conception of its 

 vastness. If a track were laid along its 

 equator, and a train were to travel 

 thereon at the rate of sixty miles an hour 

 day and night without intermission, five 

 years would be occupied in completing 

 a single journey. The sun's comparative 

 diameter might be illustrated by placing 

 109 marbles in a rov/, each one represent- 

 ing the earth. A colossal globe no doubt. 

 But we have only to look around at some 

 of the well-known stars to find the sun's 

 dimensions surpassed many times. Take 

 Sirius, the Dog Star, whose diameter is 

 six times that of the sun. At a more 

 remote distance, so remote that its dis- 

 tance cannot be correctly ascertained, is 

 Spica, a first magnitude star, which, 

 judging from its bright light, must be a 

 sphere at least "fifty-five times greater in 

 diameter than our sun. At a similarly in- 

 conceivable distance is the well-known 

 star Rigel, which Sir David Gill stated 

 must possess a minimum diamtter of 

 seventy-five times that of our luminary. 



What is the Biggest Star? 

 In ascending to greater dimensions the 



