THE NE W STAR WHICH FADED INTO STAR-MIST. 1 1 5 



would be a far greater emission at first and a far smaller 

 emission afterwards, yet it manifestly must be admitted that 

 such a collision could not possibly produce so short-lived an 

 effect as we see in the case of every one of the so-called new 

 stars. The diminution in the emission of light and heat 

 from the maximum to one-half the maximum would not 

 occupy fifty millions of years, or perhaps even five million or 

 five hundred thousand years ; but it would certainly require 

 thousands of years ; whereas we have seen that the new stars 

 in the Crown and in the Swan have lost not one-half but 

 ninety-nine hundredths of their maximum lustre in a few 

 months. 



This has been urged as an objection even to the term 

 star as applied to these suddenly appearing orbs. But the 

 objection is not valid ; because there is no reason whatever 

 for supposing that even our own sun might not be excited 

 by the downfall of meteoric or cometic matter upon it to 

 a sudden and short-lasting intensity of splendour and of 

 heat Mr. Lockyer remarks that, if any star, properly so 

 called, were to become a " a world on fire," or " burst into 

 flames," or, in less poetical language, were to be driven 

 either into a condition of incandescence absolutely, or to 

 have its incandescence increased, there can be little doubt 

 that thousands or millions of years would be necessary for 

 the reduction of its light to its original intensity. This 

 must, however, have been written in forgetfulness of some 

 facts which have been ascertained respecting our sun, and 

 which indicate pretty clearly that the sun's surface might be 

 roused to a temporary intensity of splendour and heat with- 

 out any corresponding increase in the internal heat, or in 

 the activity of the causes, whatever they may be, to which 

 the sun's steady emissions of light and heat are due. 



For instance, most of my readers are doubtless familiar 

 with the account (an oft-told tale, at any rate) of the sudden 

 increase in the splendour of a small portion of the sun's 

 surface on September i, 1859, observed by two astronomers 

 independently. The appearances described corresponded 



