Hello, I’m Jiayin Dong. I’m a 4th-year graduate student at Penn State Department of Astronomy & Astrophysics, where my advisor is Bekki Dawson. My research interests lie primarily in the formation and evolution of planetary systems. I’m excited about solving planetary-system problems using both computational and observational approaches. I was previously a predoctoral fellow at CCA, Flatiron Institute where I worked with Phil Armitage and Yan-Fei Jiang.
Research Interests. exoplanets, debris disks, planetary system formation and evolution, N-body and hydro simulations
Warm Jupiters in Year 1 TESS Full-Frame Images
Dong, Huang, Dawson et al. 2021 submitted to AJ
It is currently debated whether Warm Jupiters form in situ, undergo disk or high eccentricity tidal migration, or have a mixture of origin channels. These different classes of origin channels lead to different expectations for Warm Jupiters' properties, which are currently difficult to evaluate due to Warm Jupiters' small sample size. In this work, we systematically search for Warm Jupiter candidates around host stars brighter than the TESS-band magnitude of 12 in the Full-Frame Images in Year 1 of the TESS Prime Mission data. We introduce a catalog of Warm Jupiter candidates, characterize their transit-timing variations and eccentricities, and infer the eccentricity distribution using hierarchical Bayesian modeling.
Boundary Layer Circumplanetary Accretion
Dong, Jiang, & Armitage 2021 submitted to ApJ
Gas giants are expected to accrete most of their mass via a circumplanetary disk. If the planet is unmagnetized and initially slowly rotating, it will accrete gas via a radially narrow boundary layer and rapidly spin up. Radial broadening of the boundary layer as the planet spins up reduces the specific angular momentum of accreted gas, allowing the planet to find a terminal rotation rate short of the breakup rate. In this work, we use axisymmetric viscous hydrodynamic simulations to quantify the terminal rotation rate of planets accreting from their circumplanetary disks.
Debris Disks in Multiplanet Systems
Dong, Dawson, Shannon, & Morrison 2020, ApJ, 889, 47
Resolved debris disk features (e.g., warps, offsets, edges and gaps, azimuthal asymmetries, radially thickened rings, scale heights) contain valuable information about the underlying planetary systems, such as the posited planet’s mass, semimajor axis, and other orbital parameters. Most existing models assume a single planet is sculpting the disk feature, but recent observations of mature planetary systems (e.g., by radial velocity surveys or Kepler) have revealed that many planets reside in multiplanet systems. Are our inferences compromised by unseen planets? In this work, we investigate if/how planet properties inferred from single-planet models are compromised when multiple planets reside in the system.