[4] 51 Eridani b was announced in August 2015, but was discovered in December 2014 using the Gemini Planet Imager, an international project led by the Kavli Institute for Particle Astrophysics and Cosmology.

[6] Any residual incoming light is then scrutinized, and the brightest spots suggest a possible planet.

[6] Prior to the discovery of 51 Eridani b, each of the directly imaged worlds previously discovered had been gas giants many times the mass of Jupiter.

[10] This methane signature, along with the low luminosity of the object, should produce additional clues as to how 51 Eridani b was formed.

[5] Astronomers also detected the presence of water[11] and ammonia[12] in the planet's spectrum.