Tanga system

The Tanga system is located at the heart of an unusual rectangular planetary nebula. The inner planets were engulfed as the star entered the red giant phase. The expanded habitable zone unfroze a small world on the former outer ring and for several hundred million years made it habitable. Life began to emerge and was just reaching a primitive state when the star collapsed into a white dwarf, throwing the planet back into a deep freeze, then blasting the atmosphere away with the resulting planetary nebula. That's how the system was found: Only two worlds (speculation that there could have been three to four more) but both are dead planets with no atmosphere.

Tanga
Tanga is a Main Sequence Dwarf-A star.

Tanga I
A former gas giant that scientists believe lost its atmosphere when Tanga's star turned into a red giant. The remaining core is classified as a chthonian planet and is heavy in mineral deposits.

Tanga II
An ice planet subliming due to the system's increased temperature courtesy of the red giant. As a result, a trail of expelled gases follows Tanga II around in orbit.

Tanga Belt Alpha
Rich in a variety of precious and heavy metals that scientist theorize are the remnants of the system's former inner planets before the star expanded.