Red Rectangle

1987, Beverly T. Lynds, “Optical observations of nebulae”, in A. Dalgarno and David Layzer (eds.), Spectroscopy of astrophysical plasmas, Cambridge University Press, →ISBN, page 12, The Red Rectangle is only one example of an infrared object that is detectable in the infrared because of grain emission.

1995, J.R. Miles, P.J. Sarre, and S.M. Scarrott, “Red Rectangle Emission Bands”, in Alexander G.G.M. Tielens and Theodore Peck Snow (eds.), The Diffuse Interstellar Bands, Springer, →ISBN, page 143, The Red Rectangle is a bipolar nebula with a remarkable spectrum in which emission is excited by the light of the central star HD44179.