KELT-23Ab: A Hot Jupiter Transiting A Near-Solar Twin Close To The TESS And JWST Continuous Viewing Zones

We announce the discovery of KELT-23Ab, a hot Jupiter transiting the relatively bright (V = 10.3) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields host-star properties of Teff = 5900 ± 49 K, M* = 0.945 ((+0.060)/(-0.054))M⊙, R* = 0.995 ± 0.015 R⊙, L* = 1.082 ((+0.051)/(-0.048)) L⊙, log g* = 4.418 ((+0.026)/(-0.025) (cgs), and [Fe/H] = -0.105 ± 0.077. KELT-23Ab is a hot Jupiter with a mass of Mp = 0.938 ((+0.045)/-0.042)) M3, radius of Rp = 1.322 ± 0.025 R3, and density of P = 0.054 ((+0.038)/(-0.035)) g cm−3. Intense insolation flux from the star has likely caused KELT-23Ab to become inflated. The time of inferior conjunction is T0 = 2458149.40766 ± 0.00091 BJDTDB and the orbital period is P = 2.255353 ((+0.000031)/(-0.000030)) days. There is strong evidence that KELT-23A is a member of a long-period binary star system with a less luminous companion, and due to tidal interactions, the planet is likely to spiral into its host within roughly a gigayear. This system has one of the highest positive ecliptic latitudes of all transiting planet hosts known to date, placing it near the Transiting Planet Survey Satellite and James Webb Space Telescope continuous viewing zones. Thus we expect it to be an excellent candidate for long-term monitoring and follow up with these facilities

Observation of interspecies ion separation in inertial-confinement-fusion implosions

We report direct experimental evidence of interspecies ion separation in direct-drive, inertial-confinement-fusion experiments on the OMEGA laser facility. These experiments, which used plastic capsules with D2/Ar gas fill (1% Ar by atom), were designed specifically to reveal interspecies ion separation by exploiting the predicted, strong ion thermo-diffusion between ion species of large mass and charge difference. Via detailed analyses of imaging x-ray-spectroscopy data, we extract Ar-atom-fraction radial profiles at different times, and observe both enhancement and depletion compared to the initial 1%-Ar gas fill. The experimental results are interpreted with radiation-hydrodynamic simulations that include recently implemented, first-principles models of interspecies ion diffusion. The experimentally inferred Ar-atom-fraction profiles agree reasonably, but not exactly, with calculated profiles associated with the incoming and rebounding first shock