Harold Corwin

IC 4490 is only a double star; there is no nebulosity surrounding it. There is also no mistaking the identification as Innes describes the field perfectly:

Elliptical neb. surrounding two stars as if they were the foci of an eclipse, mags 9.5 and 10. The Cor. D.M. mag. of the chief star is 9.7. In a high-power field with Lac. 6076 [= SAO 205904].

He adopts the position of the Cordoba Durchmusterung, too, so there can be no doubt as to the double star he saw.

There is just no nebulosity around the stars. It was perhaps an optical effect of some sort due to the proximity of the 7th magnitude star just 1.5 arcmin north; or it could have been as simple as bad seeing or dew on a lens somewhere in the optical chain.

― IC Notes by Harold Corwin

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

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