Red-giant branch through several distinct stages which are reflected in the outward appearance. The evolutionary stages vary depending primarily on the mass of the star, but also on its metallicity. After a main-sequence star has exhausted its core hydrogen, it begins to fuse hydrogen in a thick shell around a core consisting largely of helium. The mass of the helium core is below the Schönberg–Chandrasekhar limit and is in thermal equilibrium, and the star is a subgiant. Any additional energy production from the shell fusion is consumed in inflating the envelope and the star cools but does not increase in luminosity. Shell
Red Star OS commands on the computer if the user clicks on a correspondingly prepared link. This is probably due to a problem when processing URLs that perform functions such as Mailto or calendar without the parameters to clean up unwanted code fragments. Red Star OS Red Star OS () is a North Korean Linux distribution, with development first starting in 1998 at the Korea Computer Center (KCC). Prior to its release, computers in North Korea typically used Red Hat Linux and Windows XP Version 3.0 was released in the summer of 2013, but , version 1.0 continues to be more widely used.