NGC 1554

NGC 1554, Struve's Lost Nebula, is a list entry in the New General Catalogue of Nebulae compiled by John L. E. Dreyer. The nebula was discovered by the German-Estonian astronomer Otto Wilhelm von Struve and confirmed by Heinrich Louis d'Arrest.[1]

Reported location of NGC 1554 by Otto Wilhelm von Struve relative to NGC 1555

Dreyer describes it as

!!! var, S, R, Nn = *13

which in NGC's encoding is expanded to

a magnificent or otherwise interesting object, variable, small, round, nucleus north of a star of the 13th magnitude

The identification is uncertain; many sources think it is related to NGC 1555, Hind's Variable Nebula, but at NGC 1554's coordinates, (epoch J2000) 04h 22m 00.0s +19° 36′ 00″ there is no nebula. However, there is a 14th magnitude star, 4' west-southwest of T Tauri,[1] so there is a possibility that the nebula Struve discovered was surrounding a variable star and it only flares up every now and then (perhaps even on a centuries long cycle). Alternatively it may have been an error caused by a pair of faint stars.[2]

  1. ^ a b www.DavidDarling.info: Struve’s Lost Nebula (NGC 1554)
  2. ^ Steinicke, Wolfgang (2010). Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer's New General Catalogue. Cambridge University Press. pp. 512–513. ISBN 9781316644188.