The Blazing Brightness of the Quasars
With brightness up to thousands of times higher than that of an entire galaxy, quasars are among the most extreme objects in the Universe. Powerful natural engines, they can transform gravitational potential energy into kinetic energy and radiation with extraordinary efficiency
The 1960s were the scene of a heated debate within the scientific world. Astronomers argued in search of a theory that could explain the nature of a new class of celestial objects that looked like stars but were not stars. The first two — called 3C 48 and 3C 273 — had been discovered in the late 1950s. Many others were found in the following decade.
What made them difficult to classify was their spectrum. They looked like dim blue stars, but their spectra contained emission lines that did not correspond to any known stellar spectrum. Also, many of those pseudo-stars were associated with powerful radio sources. They were thus called quasars, a name born from the contraction of QUAsi-stellAR radio source, that is “star-like radio source.”
Already in the 1960s, some astronomers understood that the unusual lines visible in quasar spectra were lines of known elements, but…
