[2] It was discovered by the French-led CoRoT mission which detected the dimming of the parent star's light as CoRoT-3b passes in front of it (a situation called a transit).

[4] The mass of CoRoT-3b was determined by the radial velocity method, which involves detecting the Doppler shift of the parent star's spectrum as it moves towards and away from Earth as a result of the orbiting companion.

This method usually gives only a lower limit on the object's true mass: the measured quantity is the true mass multiplied by the sine of the inclination angle between the normal vector to the orbital plane of the companion and the line of sight between Earth and the star, an angle which in general is unknown.

[6] Later more detailed analysis revealed that the object's radius is similar to that of Jupiter, which fits with the expected properties of a brown dwarf with the mass of CoRoT-3b.

According to this definition, which is the one adopted by the International Astronomical Union's Working Group on Extrasolar Planets,[10] CoRoT-3b is a brown dwarf.