On The H-R Diagram, there is a special luminosity class named Class O, which includes only a few members. These celestial bodies are known as Super-Supergiant Stars.
Properties[]
Super-Supergiant Stars show a very powerful Stellar Wind, which sends into cosmos a significant part of the stellar mass, but is not strong enough to remove the whole corona.
Super-Supergiant Stars are extremely rare in the Universe. Most scientists suggest that they are only a transition stage between class I or II and the Wolf-Rayet Stars.
As a star ages, it's core produces more and more heat, forcing the star to expand and increase it's radioactive surface to reach an equilibrium state.
As the star expands, at some point, it's surface gravity becomes too week and is equaled by photon radiative pressure. When gravity is too weak to hold the outer envelope, the star starts losing it's outer envelope and becomes a Wolf-Rayet star.
It is not well known for how much a star can stay in a Super-Supergiant stage. Estimations vary from hundreds to tens of thousands of years. As this process happens, the star increases its stellar wind, changes color to blue and becomes hotter.
While the star losses mass, it also produces high amounts of X-rays.
Hosted planet[]
Around a Super-Supergiant Star, planets can exist. However, they will be flogged by a powerful Stellar Wind which might disrupt and even remove their atmospheres. Gas giants might, if they are far enough, increase their sizes with matter accreted from stellar winds.
It is questionable if terraforming will be possible on a planet orbiting such a star. As the star quickly advances to its next stage of evolution, it changes its properties fast.
Because stellar parameters will change significantly within a human lifetime, it is not feasible to terraform a planet in orbit of a Super-Supergiant Star.