Errai is an orange star in Cepheus with a giant planet and a red dwarf companion, and the next bright star the north celestial pole will pass.
At a glance
| type | orange star (class K) |
|---|---|
| distance from the Sun | 46 light-years (14.1 pc) |
| its light left it | 46 years ago |
| luminosity | 11.9 × the Sun |
| radius | 4.62 × the Sun |
| surface temperature | 4,990 K |
| constellation | Cepheus (King) |
Read off the piece’s own catalogue, the same values it draws with.
About Errai
The card lists an orange star of class K, larger and brighter than the Sun: a star that has left the main sequence and begun to grow. It has a faint red dwarf companion, and around the main star orbits a giant planet, one of the first planets to be suspected around another star.
Errai is Gamma Cephei, and its name comes from the Arabic al-rāʿī, “the shepherd”. The Earth’s axis slowly traces a circle on the sky; after Polaris, the pole will pass near Errai, and later near Alderamin.
What you see in the piece
Errai is a near neighbour, drawn orange at its true brightness. Its planet shines only by reflected light and is far too faint to see from here.
Measured or modelled
The planet is inferred from the wobble it imposes on Errai’s light, not seen directly; its exact mass depends on the tilt of its orbit.
Questions
Will Errai become the pole star?
Yes. As the Earth’s axis precesses, the north celestial pole will move away from Polaris and pass near Errai, which will then serve as the pole star.