Coronavirus Coronavirus Coronaviruses are species of virus belonging to the subfamily "Coronavirinae" in the family "Coronaviridae", in the order Nidovirales. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome and with a nucleocapsid of helical symmetry. The genomic size of coronaviruses ranges from approximately 26 to 32 kilobases, the largest for an RNA virus. The name "coronavirus" is derived from the Latin "corona", meaning crown or halo, and refers to the characteristic appearance of virions under electron microscopy (E.M.) with a fringe of large, bulbous surface projections creating an image reminiscent of a royal crown or of the solar corona.
Stellar halo dominated by stars which formed within the galaxy, and an outer region primarily composed of stars accreted through merger events. Predictions for these components include different structure and rotation directions. Observational evidence for this dual halo in the Milky Way has been claimed but contested. Studies of the Milky Way galaxy have found that approximately 0.1-1% of its total stellar mass is contained within the stellar halo, and that it extends to over 100 kiloparsecs from the galactic centre. Stellar halo The stellar halo of a galaxy refers to the component of its galactic halo containing stars. The halo extends