Class 17 nebula

A class 17 nebula was a type of nebula containing hydrogen and helium.

In 2373, the USS Voyager encountered a class 17 nebula in the Delta Quadrant containing 7,000 parts per million of sirillium. It was somewhat similar in composition to the class 11 Azure Nebula near Klingon space in the Beta Quadrant. 

Klasse-17-Nebel クラス17星雲 Klasse 17 nevel