60 FROM NEBULA TO NEBULA 



In a certain sense every meteor that roams inter- 

 stellar space can be called a star, because it may even- 

 tually develop into one; just as a babe may become a 

 man, or a larva a moth. In my vocabulary, however, a 

 star is a heavenly body already so large as by its gram- 

 static heat to be self -luminous. In the animal and vege- 

 table worlds the more highly developed types are the 

 more complex, but, strange to say, this rule is reversed 

 among the stars, for the largest and best developed are 

 the very simplest in structure. Of this sort are the 

 so-called Spectral-class B stars, which let us now con- 

 sider in some detail by way of illustrating my method of 

 star interpretation. 



Astrophysicists in classifying stars by their spectra 

 began to do so at a period when the Nebular Hypothesis 

 of Laplace was universally accepted, and although that 

 conception is now generally discredited, the old classifi- 

 cation still prevails. It was assumed that stars freshly 

 born of their nebulae are then at their best and brightest, 

 and from that time onward gradually cool, fade and de- 

 cay. In this way the mass of stars as a possible key to 

 their several peculiarities was altogether lost sight of 

 and the spurious standard of age substituted. Thus it 

 came about that the spectra of the very brightest stars, 

 intrinsically, are denominated "early", while those of 

 the duller sort are called "late". This to me seems a 

 very unfortunate error, inasmuch as it not only decides 

 the issues in advance of the investigation, but raises up 

 one more prejudice to add to the multitude already 

 crowding the path of progress. The age of a star has 

 nothing to do with a star's brightness or dullness, save 

 to the extent that the longer it has been in existence the 

 more chance has it had to grow by feeding upon the 

 flotsam of space. My rule is, simply, that the attributes 

 of stars are functioned upon their mass. The bigger 

 the star, caeteris paribus, the slower its velocity, the 

 rarer its density, the hotter its temperature, the 

 "earlier" its spectrum, the brighter and steadier its light, 

 and the longer its distinguishing cycle of variation. 



