Harold Corwin

This large diffuse nebula was discovered by Barnard and Wolf. Barnard found it and IC 63 on a plate taken 2 February 1894 with the 6-inch F5 Willard portrait lens, and confirmed them on another plate of 6 February of the same year. His paper, showing a sketch of the field, is in Astronomy and Astro-Physics 13, 177, 1894 dated 7 February 1894. He didn't tarry with his publishing! He also visually examined the field on 6 February with Lick Observatory's 12-inch at 80X and saw both nebulae, though "with utmost difficulty." He gives positions relative to gamma Cassiopeia for the nebulae, but has not reduced them to RA and Dec.

Wolf's short note on these is in AN 3214. He does not give exact dates for his plates, but says they were taken in December 1893 and January 1894; his note is dated 17 January 1894. A third new nebula noted by Wolf, IC 155 (which see), does not exist on the modern sky surveys, so is apparently a plate defect.

IC 59 is quite a bit brighter on the blue sky survey plates, befitting its identification as a reflection nebula associated with gamma Cas. IC 63 is somewhat less blue -- the star's UV light has ionized some of the hydrogen in the nebula, so H-alpha emission is prevalent across the area, too.

Barnard mentioned both objects as "two small nebulae" near gamma Cas in his splendid first collection of photographs in the Lick Observatory Publications, Volume XI, 1913. However, he did not name them, and he seems to have mostly ignored the Index Catalogue numbers throughout the volume, even when the objects themselves are clearly shown on his plates.

These two nebulae are visible in three Plates 5, 6, and 7; they are best seen in Plate 5 where gamma Cas is centered. Plate 7 was the first taken on 2 February 1894 -- this is apparently the plate he mentioned in his paper. The plate taken the following night is not included in Barnard's monograph, but Plate 6 was taken on 7 November of the same year, and Plate 5 on the next night.

― IC Notes by Harold Corwin

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