130 



ASTRONOMY FOR 1889, 1890, 

 PROPER MOTIONS. 



Professor Boss has published iu the Astronomical Journal the proper 

 motions of 295 stars of tbe Albany zone (+ (P 50' to + 5° 10'). 



In the Bulletin Astronomique for March, 1800, is a. most useful cata- 

 logue, compiled by Bossert, of all stars whose proper motion is known 

 to exceed 0."50. They are thus distributed : 



DOUBLE AND MULTIPLE STARS. 



Some very elegant and simple formuhe for determining the true orbit 

 of a binary star, originally published in Kussiau, have been brought 

 out by Professor Glasenapp. 



? Scorpii. — Herr Schorr has made a study of the motious iu this 

 trii>le system by methods similar to those employed by Dr. Seeliger on 

 C Cancri. The star is known as - 1998, the magnitudes of its compo- 

 nents being A = 3.9, B = 5.2, O = 7.2. 



ry Ophiuchi has been divided into two nearly etiaal components by 

 Burnham with the 30 inch Lick telescope, and he thinks that it will 

 prove to be a binary of short period. He has also found companions 

 for Aldebaran, y Cassiopeije, and (5C>gni, and has been able to sepa- 

 rate and nu^asnre a c()ini)anion to the principal star in the pair e Ilydne, 

 the existence of which was suspected by previous observers. 



Photographs of the si)ectrum of Spica have put beyond question the 

 reality of its motion in the direction of the line of sight. Dr. Yogel 

 has deduced from observations of 1889 and 1890 a period of revolution 

 of about 4 days. 



PHOTOMETRY. 



The results ot observations made with the meridian photometer of 

 the Harvard observatory by Prof. E. C. Pickering and Mr. Wendell 

 during the years 1882 -1888, have appeared as volume 24 of the Harvard 

 Annals. The i)rincipal work done with this instrument was "the de- 

 termination of the magnitudes of a sufficient number of stars con- 

 tained iu the Durchmusterung, aiul distributed with approximate uni- 

 formity, to serve for future estimates or measures of magnitude, and 

 to enable previous estimates to be reduced tathe photometric scale," 



