K2-139 b : A low-mass warm Jupiter on a 29-d orbit transiting an active K0 V star
We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547± 25 K) on a 29-d orbit around an active (logR' HK =-4.46±0.06) K0V star in K2 Campaign 7.We derive the system's parameters by combining the K2 photometry with groundbased follow-up observations. With a mass of 0.387 -0.033+0.075 MJ and radius of 0.808 -0.033+0.034 RJ, K2-139 b is one of the transiting wa