In a discovery decades in the making, scientists have detected a new theoretical class of stars first proposed in 1975 by physicist Kip Thorne and astronomer Anna Zytkow. Thorne-Zytkow Objects (TZOs) are hybrids of red supergiant and neutron stars that in many ways resemble normal red supergiants, such as Betelgeuse. They differ, however, in the distinct chemical signatures that result from unique activity in their stellar interiors. A TZO forms when a massive red supergiant essentially swallows a neutron star, which spirals into the core of the red supergiant. While normal red supergiants derive their energy from nuclear fusion, TZOs are powered by the unusual activity of the absorbed neutron star at the core.