TESS Hunt for Young and Maturing Exoplanets (THYME). II. A 17 Myr Old Transiting Hot Jupiter in the Sco-Cen Association

<jats:title>Abstract</jats:title> <jats:p>We present the discovery of a transiting hot Jupiter orbiting HIP 67522 (<jats:italic>T</jats:italic> <jats:sub>eff</jats:sub> ∼ 5650 K; <jats:italic>M</jats:italic> <jats:sub>*</jats:sub> ∼ 1.2<jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) in the 10–20 Myr old Sco-Cen OB association. We identified the transits in the TESS data using our custom notch filter planet search pipeline and characterize the system with additional photometry from Spitzer; spectroscopy from SOAR/Goodman, SALT/HRS, LCOGT/NRES, and SMARTS/CHIRON; and speckle imaging from SOAR/HRCam. We model the photometry as a periodic Gaussian process with transits to account for stellar variability and find an orbital period of <jats:inline-formula> <jats:tex-math> <?CDATA ${6.9596}_{-0.000015}^{+0.000016}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ajab94b7ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> days and radius of <jats:inline-formula> <jats:tex-math> <?CDATA ${10.02}_{-0.53}^{+0.54}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ajab94b7ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> <jats:italic>R</jats:italic> <jats:sub>⊕</jats:sub>. We also identify a single transit of an additional candidate planet with radius <jats:inline-formula> <jats:tex-math> <?CDATA ${8.01}_{-0.71}^{+0.75}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ajab94b7ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> <jats:italic>R</jats:italic> <jats:sub>⊕</jats:sub> that has an orbital period of ≳23 days. The validated planet HIP 67522b is currently the youngest transiting hot Jupiter discovered and is an ideal candidate for transmission spectroscopy and radial velocity follow-up studies, while also demonstrating that some young giant planets either form in situ at small orbital radii or else migrate promptly from formation sites farther out in the disk.</jats:p>