Smithsonian Report. 1942. Fleming 



Plate 1 9 



Photographs of the Aurora Borealis Which Accompanied the Geomag- 

 netic STORM OF September 18. 1941 



(AH times are mean 75° west meriiliaii.) 

 (.1) igi-lOn'; corona, just south of Vega, was formed by the rayed band .shown in (C) of this plate and (.4) 

 of plate 18; exposure 10 seconds. (/?) 22i'50"'; very beautiful rayed band in the northwest; shows very 

 narrow ray-structure which seems to be eharaclerisfie (jf a peak i^f a displax'; l(]wer Ixirder of r;iys « :is ird 



and they wen- in ralher rapid molion: lliis is a fiiii' drapi ry; i\|i(iMirc :', MiorK 

 band north <if west shcjws cnnverijcnee of rays; exposuir .'. scchikIs. ' Ji oli.'.p 

 in northwest; bright star at left is Vega; shows the ("'ginning (il the main plia^- 

 great display, actually the beginning of great display: exiuisure ■V\ sceciiids. 

 -\. Y.. by C. \V. Gartlein and courtesy of Xational • u'uyraphii' .Sdiiet;..) 



{(') I'.II'lS'": tine |-;l.\ei| 



, arc and tmrsohne em \ es 

 iif aurora on night tielore 

 ( I'hntographs at Ithaca, 



