264 



Compared 

 with others. 



ON THE PLANET VESTA. 



clear, I used a 10-feet reflector with a low power to examine 

 it. There was no visible nucleus, nor did the light which is 

 called the coma increase suddenly towards the centre, but 

 was of an irregular round form,- and with this low power 

 extended to about 5, 6, or 7 minutes in diameter. When 

 I magnified \6Q times it was considerably reduced in size, 

 which plainly indicated, that a farther increase of magnify- 

 ing power would be of no service for discovering a nucleus. 

 On account of cloudy weather I never had an opportunity 

 of seeing the comet afterwards. 



When I compare these observations with my former ones 

 of 15 other telescopic comets, I find, that, out of the 16 

 which I have examined, 14 have been without any visible so- 

 lid body in their centre, and that the other two had a very ill 

 defined small central light, which perhaps might be called a 

 nucleus, but did not deserve the name of a disk. 



V. 



Observations and Measurements of the Planet Vesta, 

 John Jerome Schroeter, F.R.S.* 



Planet Vesta 

 has no disk 

 with a power 

 of 300, 



and an intense 

 radiating light, 

 like a star of 

 the 6th magni- 

 tude. 



The same with 

 Other tele- 

 scopes. 



By 



T our very first observations with magnifying powers of 

 150 and 300 applied to the excellent new 15-feet reflector, 

 we found the planet Vesta without any appearance of a disk, 

 merely as a point like a fixed star with an intense, radiating 

 light, and exactly of the same appearance as that of any fixed 

 star of the sixth magnitude. In the same manner we both 

 afterwards saw this planet several times with our naked eyes, 

 when the sky was clear, and when it was surrounded by 

 smaller invisible stars, which precluded all possibility of mis- 

 taking it for another. This proves how very like the intense 

 light of this planet is to that of a fixed star. 



As the observations and measurements of Ceres, Pallas, 

 and Juno, were made with the same eye-glasses, but with 

 the 13-feet reflector, we soon after compared the planet 

 Vesta with the same glasses of 136 and 288 times magnify- 



« From the Philos. Trans, for 1&07, Pa:t II, p. 245. 



mg 



