384 Professor IT. U. Turner [June 5, 



T CoronaB, the star was indeed previously known as an ordinary star. 

 In this connection, our recent discovery at Oxford is of special in- 

 terest. By great good fortune, it appeared in a region of which 

 previous records were exceptionally good, for both Dr. Max Wolf at 

 Heidelberg, and Mr. Parkhurst at the Yerkes Observatory, had taken 

 photographs of the region within a month before the outburst, showing 

 very faint stars, to the fifteenth or sixteenth magnitude ; and a very 

 faint object was seen to be in or near the position subsequently 

 occupied by the Nova. With great kindness, Dr. Max Wolf im- 

 mediately sent to us copies of his photograph of February 16, and 

 we measured at Oxford with every care the positions of the Nova 

 and the star suspected to be identical with it. Our verdict is that 

 the positions are not identical, but that there is a difference of some 

 seconds of arc. The photographic images are, however, rather in- 

 definite, and this judgment may be reversed on appeal to Mr. Park- 

 hurst's plate, which we have not yet seen. In any case, the existence 

 of these two plates will carry the inquiry as to the previous history of 

 Novas one step forward, and our Oxford discovery will have made its 

 contribution to this department of astronomy. 



A second point worthy of notice is that all the new stars hitherto 

 discovered lie in or near the Milky Way. So many facts concerning 

 the distribution of the stars group themselves about the Milky Way 

 that we must regard this wonderful belt as of fundamental importance 

 in the structure of the visible universe. There is, for instance, another 

 class of stars only found near the Milky Way, called Wolf-Rayet 

 stars ; and it is characteristic of the Harvard Observatory that nearly 

 all of these objects have been discovered there by the examination 

 of photographic plates. We have not time for more than a glance 

 at the possibilities here opened up ; but a mere glance is sufficient 

 to indicate the important part played by these objects in the history 

 of our stellar system. It is not too much to say that they may be the 

 key which will unlock the approaches to stores of knowledge hitherto 

 undreamt of. 



And it follows that we must pay much more attention to the 

 discovery of new stars in the future. It is practically certain that 

 those hitherto discovered are only a few cases, and probably extreme 

 cases, of events which are constantly happening in lesser degrees. 

 The Harvard systematic search has produced about one new star 

 per year, and we have every reason to believe this is only a fraction 

 of the truth. Accepting it, however, as the whole truth, then during 

 the millions of years which physicists, biologists and geologists 

 concur in demanding for the past of our solar system, there must 

 have been millions of such occurrences. If we are right in thinking 

 that the subjects of such disturbances are ordinary stars like our Sun, 

 may it not be that many of the stars we see have undergone one or 

 more vicissitudes ? May not our sun himself have been a " new star " 

 at least once ? The accession of heat cannot have been so great as in 

 the case of Nova Persei for instance, or we should liavo been blown 



