Gamma Cephei Ab is an exoplanet approximately 45 light-years away in the constellation of Cepheus (the King). The planet was confirmed to be in orbit around Gamma Cephei A in 2002, but was first suspected to exist around 1988 (making this planet arguably the first true exoplanet discovered).
On September 24, 2002, Gamma Cephei Ab was finally confirmed. The team of astronomers (including William D. Cochran, Artie P. Hatzes, et al.) at the Planetary Systems and their Formation Workshop announced the preliminary confirmation of a long-suspected planet Gamma Cephei Ab with a minimum mass of 1.59 MJ (1.59 times that of Jupiter). The parameters were later recalculated when direct detection of the secondary star Gamma Cephei B allowed astronomers to better constrain the properties of the system. Gamma Cephei Ab moves in an elliptical orbit with a semimajor axis of 2.044 AU which takes almost two and a half years to complete. The eccentricity is 0.115, which means it moves between 1.81 and 2.28 AUs in orbital distance around Gamma Cephei A, which would place it from slightly beyond the orbit of Mars, to the inner Asteroid belt in the solar system.
Hipparcos data taken in 2006 constrains its mass below “13.3 MJ at the 95% confidence level, and 16.9 MJ at the 99.73% (3 ?) confidence level”. This is not much to go on, but it is enough to verify that it is not another unseen brown or red dwarf.
Credit : Fandom
Picture Credit : Google