Caption: A synthetic continuous spectrum (in image representation, NOT flux representation) mimicking the Solar spectrum from range 385--765 nm (i.e., approximately the visible band (fiducial range 0.4--0.7 μm)) with the Fraunhofer lines artificially superimposed. The Fraunhofer lines are the strongest solar absorption lines. There are far more weaker ones. See a real solar spectrum at solar_spectrum_image.html.

Features:

1. The Solar spectrum is the most famous absorption line spectrum.

   The strongest absorption lines (i.e., the Fraunhofer lines) were discovered secondly in 1814 and named with letters by Joseph von Fraunhofer (1787--1826) (see Wikipedia: Fraunhofer lines: Discovery). Nothing about their origin in atoms and molecules was known at that time. The understanding of spectroscopy developed gradually in the course of the 19th century and 20th century (see Wikipedia: History of spectroscopy).

   Note some Fraunhofer lines were discovered firstly by William Hyde Wollaston (1766--1828) in 1802.

2. The Fraunhofer lines are tabulated at Wikipedia: Fraunhofer lines: Naming.

3. Some of the absorption lines in the solar spectrum are telluric lines---they are caused by absorption in the Earth's atmosphere. Telluric lines are traditionally regarded as part of the Fraunhofer lines because they are lines observed by Fraunhofer. Telluric lines are usually removed in modern stellar spectroscopy because they are NOT intrinsic to the nature of stars, and so tell nothing about stars.