2026AJ....171..142W

We present the second set of discoveries from Keck Observations in the INfrared of Taurus and ρ Oph Exoplanets And Ultracool dwarfs (KOINTREAU), an adaptive optics survey of young stars in the Taurus and ρ Oph star-forming regions using Keck/NIRC2 in conjunction with the Keck infrared pyramid wavefront sensor. We have discovered two faint comoving companions to young stars ISO-Oph 96 and 2MASS J16262785-2625152. The companion to ISO-Oph 96, KOINTREAU-3b, is at a projected separation of 340 au (2$\mathop{.}\limits^{\unicode{x02033}}$49). Using our NIRC2 photometry and evolutionary models, and assuming that the companion has the same extinction as its host star, we infer that KOINTREAU-3b has a mass of 3.4 ± 0.7 M_Jup. The companion to 2MASS J16262785-2625152, KOINTREAU-4b, has a projected separation of 180 au (1$\mathop{.}\limits^{\unicode{x02033}}$25) and could have a mass of either $11.{5}_{-1.6}^{+1.2}$ M_Jup or $15.{3}_{-0.8}^{+0.7}$ M_Jup, depending on whether the host star is a member of ρ Oph or Upper Sco.