March, 1913. 



KNOWLEDGE. 



113 



Mars is a morning Star, but practically invisible. 



Jupiter is still badly placed, having been in conjunction 

 with the Sun on December 18th. It is a morning star. Polar 

 semi-diameter, I83". 



Table 21. 



Configurations of Jupiter's satellites at 3 h m for an inverting 

 telescope. 



Satellite phenomena visible at Greenwich, l d 3 h 9 m II. Oc. 

 R. ; 4 h 40 ra 15 9 III. Ec. R. ; 4 d 5 h 16 m 11 s IV. Ec. D. ; 

 6 d 3 h 33 m I. Sh. I.; 4 h 51 m I. Tr. I.; 7 d 4 h 25 m I. Oc. R.; 

 12 d 3 h 54 m III. Tr. E. ; 13 d 4 h 3 m IV. Tr. E. ; 14 d 2 h 45 m 15 s 

 I. Ec. D. ; 15 d 2 h 11™ I. Sh. E. ; 2 h 56 m 58 s II. Ec. D. ; 3 h 29 m 

 I. Tr. E. ; 17 d 3 h 13 m II. Tr. E. : 19 d 2 h 32™ III. Sh. E. 

 4 h 34 m III.Tr. I.;21 d 4 h 38 m 57 s I. Ec. D. ; 22 d l h 47 m I. Sh. I, 

 3 h 3 m I. Tr. I.; 4 h 5 ra I. Sh. E. ; 23 d 2 h 39 m I. Oc. R. 

 24 d 2 h 56 m II. Tr. I.; 3 h 10 m II.Sh.E. ; 26 d 3 h 25 m III. Sh. I. 

 29 d 3 h 41 m I. Sh. I. ; 30 d l h l m I. Ec. D. ; l h 45 m III. Oc. R. 

 4 h 30 m I. Oc. R. 



All the above are in the morning hours. 



Saturn is an evening Star, 6° South-east of the Pleiades. 

 Polar semi-diameter 8". The major axis of the ring is 39", the 

 minor axis 17". The ring is now approaching its maximum 

 opening and projects beyond the poles of the planet. 



The planet is too near the Sun for convenient observation 

 of the satellites. 



Uranus is a morning star, but badly placed, having been 

 in conjunction with the Sun on January 24th. 



Neptune was in opposition on January 14th and is 

 stationary on April 4th. Its motion may be traced on the 

 map of small stars which was given in " Knowledge " for 

 December, 1911, page 476. 



Meteor Showers (from Mr. Denning's List) : — 



Double Stars and Clusters. — The tables of these given 

 last year are again available, and readers are referred to the 

 corresponding month of last year. 



Variable Stars. — Tables of these will be given each 

 month ; the range of R.A. will be made four hours, of which 

 two hours will overlap with the following one. Thus the 

 present list includes R.A. 10 h to 14 h , next month 12 h to 16 h , and 

 so on. In the case of Algol variables, the time of one 

 minimum is given where possible, and the period. Algol, 

 owing to its brightness, will be given for wider limits. 



Table 22. 

 Algol Stars. 



Non-Algol Stars. 



