This was in development for months and has been sitting on my computer since July and I'm finally uploading it. I never considered it ready, and I still don't, but I'd like to put it out there before I forget about it. This mod will hopefully be improved in the future.

A mock playthrough of the planet was done a while ago, assuming fully autonomous factories on the prerequisite planets. I'm hoping that the 2.1 migration didn't break anything since then. Assuming it didn't, the planet should be possible, given that you are prepared with the necessary items and machines. The final product of that playthrough is shown in the gameplay image you can find in the gallery.

Main Description:

Planet Linox not good enough for you? Try this mod and land directly on the surface of a star!
Helios is a "planet" centered around extreme-temperature manufacturing, plasma processing, and advanced materials like silicon. While inspiration was taken from real astrophysics, a significant amount of realism obviously had to be sacrificed to make this possible and enjoyable in the slightest. That being said, expect longer production chains than the standard Space Age planets, with a heavy emphasis on fluids and byproducts. Additionally, similarly to Aquilo, be sure to prepare your character and factories before traveling to Helios for the first time, or else you risk getting stranded. Helios is very barren and dependent on imports until it's fully established, and even then, it is not fully self-sufficient. Helios is strongly connected to Vulcanus, its closest neighbor.

Credits:

The I.M.P. graphics were made by Hurricane046. View CREDITS.txt in the mod folder for other graphics attributions.
The background music present on Helios originates from Azure Mines and was composed by Evanbear1.

TL;DR Planet Summary:

Accessible after Vulcanus and Fulgora are completed. Extremely hot (bring energy shields to prevent an infinite death loop). Many recipes involve several fluids at once and multiple byproducts. Relies on imports, but not as much as Aquilo. The planet's resources integrate with the tech tree for the endgame (e.g. quantum processors) and also adds new tiers of certain things (e.g. energy shield).