Two of this class of objects' discoverers noted their prominent hydrogen, sulfur, and oxygen lines, and Viktor Hambardzumyan named these entities
Four new examples of this type of object were reported in 2012 by Travis Rector and Heidi Schweiker in NGC7023, although one object, 450X, thought previously to be another example located in Bok globule B175, has been reclassified as a background galaxy. In the mid-to-late 1990s, several examples were found to be up to 10 parsecs, over 30 times larger than most previously observed examples. Two of this class of objects' discoverers noted their prominent hydrogen, sulfur, and oxygen lines, and Viktor Hambardzumyan named these entities (*) after those two men. An analogue of these structures, which manifests at lower frequencies, is called a Molecular Hydrogen emission-line Object. They were first observed by Sherburne Wesley Burnham, who noted nebulosity around T Tauri, and always occur almost perpendicular to the protoplanetary disk. For 10 points, name these shockwaves in the interstellar medium, formed as narrow jets of hot gas collide with cold dust around newly-born stars.
Four new examples of this type of object were reported in 2012 by Travis Rector and Heidi Schweiker in NGC7023, although one object, 450X, thought previously to be another example located in Bok globule B175, has been reclassified as a background galaxy.
Herbig-Haro objects