| HK line comparison table | ||
| Subject | has definition | is a kind of | 
|---|---|---|
| interstellar line | Sharp, distinct absorption lines superposed on stellar spectra, produced by the interstellar gas located between the source and the observer. Strongest are the D lines, followed by the H and K lines, and the K I doublet at 7699 and 7644 Å. | absorption line | 
| HK line | interstellar line | 
Next interstellar line: D line     Up: interstellar line