astrovirus

noun

as·​tro·​vi·​rus ˌa-strə-ˈvī-rəs 

: any of a family (Astroviridae) of single-stranded RNA viruses that infect vertebrates causing gastroenteritis in humans and especially children

We conclude that astroviruses are medically important agents of gastroenteritis that produce clinical findings similar to those caused by rotavirus infection.

—John E. Herrmann et al., The New England Journal of Medicine

Note: Astroviruses have a spherical virion with no lipid envelope. The surface structure often appears star-shaped with five or six points when viewed with an electron microscope.