Some of the Henize emission nebulae are so staggeringly big and bright, and infused with such rich shades and detail, that it’s hard to believe they reside in another galaxy

The Large Magellanic Cloud is swarming with a magnificent array of emission nebulae. They appear in all shapes and sizes, from the stupendous Tarantula Nebula… to the enormous superbubbles and star-birth regions… to intricate complexes… to beautiful bubble-shaped nebulae… to blobs… to small and almost stellar nebulae. And thanks to the American astronomer and astronaut, Karl Henize (1926-1993), we observers have a truly spectacular observing guide. He was stationed at Lament-Hussey Observatory, Bloemfontein, South Africa, from 1948-1951, where he conducted an objective-prism spectroscopic survey of the southern sky for stars and nebulae showing emission lines of hydrogen. In 1956 he published the results of an extensive survey of both Magellanic Clouds for emission line objects, stars and nebulae (five catalogues – three for the LMC and two for the SMC).

His “Catalogue of Emission Nebulae in the Large Cloud” lists 221 emission nebulae, many of which have associated nebular components (for a total of 415). As he explained, “Many of these objects are bright knots that lie in fainter patches of nebulosity. In view of the impossibility of making a significant distinction between isolated Nebulae: and knots embedded in a faint nebulous background, all bright knots, whether or not they are associated with larger fields of nebulosity, are described as separate objects. An attempt has been made to indicate a close relationship between a group of knots involved in a nebulous background by assigning the knots the same number as the background nebulosity and designating the individual knots by letters of the alphabet assigned in the order of the brightness of the knots. In some instances, groups of knots that seem to be physically related, even though no connecting background nebulosity is visible, have been assigned a group number.”  His catalogue included planetary nebulae and stellar objects and some objects turned out to be supernova remnants.

Although the nebular components are designated N, the full names of his entries are thus, using his first entry as the example: LHa120-N1. “L” refers to the Lamont-Hussey Observatory of the University of Michigan. “Ha” means the Hydrogen-alpha emission line, the key signature line used in the survey. “120” refers to the plate number (objective prism plate) for the LMC. “N” labels the object as a nebula, as distinct from a star, (label “S”).”1” is the first entry in his catalogue.

Karl Henize at Lament-Hussey Observatory, Bloemfontein, South Africa.

The Tarantula Nebula, the superbubbles, the fiery star birth regions…  the radiance of these exquisite objects is spectacular! In fact, words are inadequate to describe the way they shimmer with every gradation of nebulous light and display incredible depth and detail. Martin Luther King put it best: “Occasionally in life there are those moments of unutterable fulfillment which cannot be completely explained by those symbols called words. Their meanings can only be articulated by the inaudible language of the heart.”