204 Proceedings of the Royal Irish Academy. 



On the evening of its discovery, Schmidt considered the star to be 

 a strong golden yellow, and that afterwards it remained of a deep 

 yellow, but at no time was it so ruddy as the neighbouring 75 Cygni. 

 Schmidt observed the constellation Cygnus on several occasions be- 

 tween ]!^ovember 1 and 20, and is certain that no star of even 5 m. 

 could have escaped his notice, so that the star must have blazed out 

 very suddenly. Between November 20 and 24 the weather was 

 cloudy, so the exact time of its appearance is unknown. The star was 

 examined with the spectroscope a few days after its discovery ; and 

 its spectrum showed bright lines similar to those of T Coronse in 1866. 

 One of the bright lines is supposed to be identical with the line 1474 

 Kirchoff, visible in the spectrum of the solar corona. The other bright 

 lines were identified by M. Cornu, of the Paris Observatory, with some 

 of the lines of hydrogen, sodium, and magnesium. 



The star would seem to be quite new, as there is no star in any of 

 the catalogues in the position of the Nova. The nearest registered 

 star is one about 9 m., which is found in the Bonn observations. 

 When the star had faded to 7 m., it was considered by some observers 

 to be colourless, whereas by others it was thought to be decidedly 

 orange. I could see no trace of colour in the star with a 3-inch re- 

 fractor on January 13th, 1877 (when first seen in the Punjab), but it 

 had then faded to the 8th magnitude. On February 7th, 1877, I 

 estimated it 9 m. 



The place of the Nova is situated south of, and a little/., 75 Cygni. 

 A little south of it is Lalande 42383. (8 m). In September, 1877, 

 the star was spectroscopically examined with a 15-inch refractor by 

 Lord Lindsay, who found "the light coming from it almost entirely 

 monochromatic, the star appearing exactly the same as when looked at 

 without the spectroscope, the direct prism having no effect on it." 

 He considers " that there is little doubt but that this star has changed 

 into a planetary nebula of small angular diameter." On September 

 3rd the mag. was 10-5; ^' faint blue near another star of same size 

 rather red." 



Schmidt, with the Athens refractor, has observed three small stars 

 near the variable, with the following differences of right ascension and 

 declination : — 



13 m. 



y = Nova - P"0 



Nova - 45" 



13 . 



. %= „ -VQ 



„ -81 



12-5 



a;= ,, +4-6 



„ +20 



Por details of the spectrum of this curious object see Won. Notices of 

 R. A. S., Vol. XXXYIIL, No. 4, Peb., 1878. 



Dr. Yogel considers that the theory of the star having changed into 

 a planetary nebula is inadmissible, the wave length of the stellar line 

 being 4990 ±10, whereas the wave lengths of the three nebulous lines 

 are 5003, 4957, and 4861, of which the second is the most charac- 



