Gliese 667 Cc

Lore & Background

Unlike our Sun’s yellow-white burn, this star radiates primarily in infrared. Orbiting every 28 days, it is almost certainly tidally locked. One hemisphere bakes under eternal noon while the other freezes in permanent night. Survival hinges on atmospheric circulation models that might ferry heat from the scorching day side to the frozen dark, potentially sustaining liquid water in a perpetual twilight terminator zone or across a global ocean.

In Their Own Story

The twin suns of A and B hung as distant, bright pinpricks in the violet-black sky, mere ornaments to the true master: C. It loomed large and angry red, a bloated eye staring unblinkingly at the surface below. Here, on the terminator line where day bled into night, the wind howled with a constant, low-frequency rumble, carrying the scent of wet basalt and ozone. There was no sunrise or sunset here; only the eternal, shifting gradient of twilight. The ground was a mosaic of dark silicate rocks, shimmering under the dim red light, while patches of greenish-brown lichen-like growths clung to the damp crevices where condensation from the atmosphere gathered. In the distance, a vast ocean stretched toward the horizon, its surface calm and reflective like polished obsidian, absorbing the weak infrared heat. It was a world of extremes held in precarious balance, where survival depended not on conquering the heat or cold, but on inhabiting the narrow strip between them.

Reader's Guide

This host star is significantly cooler and dimmer than our Sun, emitting most of its energy in the infrared spectrum. Consequently, for a planet to maintain liquid water on its surface, it must orbit much closer to the star than Earth does to the Sun. It has a minimum mass of approximately 4.5 times that of Earth, classifying it as a super-Earth. Its orbital period is roughly 28.1 days, placing it firmly within the conservative habitable zone where stellar flux allows for surface water. The planet's habitability hinges on several factors, primarily its atmospheric composition and potential tidal locking. Due to its close orbit, it likely rotates synchronously with its star, meaning one side is in permanent daylight and the other in eternal night. Models suggest that a thick atmosphere could circulate heat effectively, preventing the day side from boiling and the night side from freezing, potentially creating a habitable region along the twilight terminator or across a global ocean.

Did You Know?

• Detection relied on the European Southern Observatory’s HARPS instrument, which tracked the star's tiny gravitational wobble caused by the planet's pull.
• Though a mere 23 light-years distant, its small size and dim host star render it nearly invisible to current direct imaging technology.