Make one sphere for your planet texture and make another sphere, slightly larger, with 95% transparency.

Set the Diffuse Render Shader for the transparent sphere to "Planet Glow"

In the Planet Glow options:

• Set "Halo Starts" to something high, like 95%.
• Set "Halo Glow" to something low, like 5%.

Plop the model in a Chor.

In the camera properties, set Render Options > Plugin Shaders to ON.