emission-line object

The term emission-line object is often used for sources that raise interest because they show a clear emission line or lines, particularly if the observed line is insufficient to identify the type of object. The term is often used for such objects discovered in surveys. Some surveys motivated to find instances of some particular type of emission-line object find numerous object-types, later classified through analysis. (Thus the survey-results can be re-used to look for other types.) Some of the types of objects that include emission lines:

• Be stars.
• emission line galaxies.
• emission-line stars.
• Herbig AeBe stars.
• Herbig-Haro objects.
• LINERs.
• planetary nebulae.
• Seyfert galaxies.
• shell stars.
• submillimeter galaxies.
• T-Tauri stars.
• Wolf-Rayet stars.