We propose to conduct an end-to-end ground-based telescopic survey for a hypothesized distant massive planet in our solar system. Such a planet was suggested by trujillo and sheppard (2014) to explain…

This federal contract award to Northern Arizona University (NAU) is for a research project focused on conducting a ground-based telescopic survey to search for a hypothesized distant massive planet in our solar system. The $536,220.47 grant is being funded by the National Aeronautics and Space Administration (NASA) under its Planetary Astronomy (PAST) program. The research aims to either discover this hypothesized planet or rule out its existence through a multi-pronged approach involving dynamical simulations, wide-area surveys, and observational bias modeling. As a public research university, NAU has extensive expertise in planetary science, remote sensing, and STEM research that it leverages to support NASA's space exploration objectives. This award does not have a set-aside designation, reflecting NAU's competitiveness in securing federal research grants across various scientific disciplines.

We propose to conduct an end-to-end ground-based telescopic survey for a hypothesized distant massive planet in our solar system. Such a planet was suggested by trujillo and sheppard (2014) to explain the orbital alignment of the most distant objects in the solar system, the dozen known extreme trans-neptunian objects (etnos) and the two known inner oort cloud objects (iocs), sedna and 2012 VP113. Brown and batygin (2016) have since provided a preliminary orbit and done extensive dynamical simulations to show that a 10 earth mass planet beyond 500 AU could explain the orbital properties of the etnos, iocs and the high-inclination tnos. While tacitly seeming far-fetched, the existence of such a planet is poorly constrained by current observational surveys. However, many exoplanet systems are known with sub-uranus mass planets on highly elliptical orbits, and our solar system may not be an exception. As such, many works in the past year have considered the observational and dynamical implications of such a planet in our solar system. Our proposal seeks funding under planetary astronomy (past) for new ground-based telescopic observations of the solar system which support the NASA exploration objective of ascertaining the content, origin, and evolution of the solar system. We will use a three-pronged approach that will either discover the hypothesized planet or rule out its existence: (1) we will conduct dynamical simulations of the known etnos and iocs to constrain the possible sky location of the hypothesized massive planet. We have already begun this process by running thousands of dynamical simulations to constrain the planet location to an area of several hundred square degrees (trujillo ET AL 2017). (2) we will combine the focused survey area above with a more general wide-area survey of thousands of square degrees in both the northern and southern hemisphere at many ecliptic longitudes. Such a wide sky area survey is useful for detecting more etnos/iocs which will constrain our dynamical models further. In addition, IT will provide the least biased survey possible to uncover the true population distribution of the etnos and iocs. In the past, most surveys have targeted relatively small areas of sky and been biased in terms of longitude/latitude coverage. We will use ground-based survey telescopes in both hemispheres to reduce latitude bias (the cerro tololo dark energy camera in chile and subaru hyper suprimecam in hawaii). (3) we will use our observational bias simulator to model the biases that are present in our survey to determine the true populations of the etnos and iocs. While our wide-area survey will be the least-biased survey specifically targeting the etnos/iocs and the hypothesized planet, there are still biases present in any survey. We have already developed methods to DE-bias our survey and provide true population estimates of the etnos and iocs (sheppard and trujillo 2016). Additionally, we will test specific hypothesized massive planet orbits and estimate the detectability of those orbits. This will allow US to estimate the overall probability of detection of the hypothesized planet and constrain the null hypothesis that the massive planet does not exist. We believe that our proposed approach will provide the highest probability of detecting or ruling out the presence of the hypothesized planet because of our closed-loop methodology. First, we predict the location of the hypothesized planet using the known etnos and iocs and survey that area. Second, we will conduct an unbiased wide-area survey to discover more etnos and iocs. Third, we will use our observational bias simulator to determine the population properties of the etnos/iocs and feed this back into our dynamical simulations. This cycle will be repeated over the course of our experiment until we find the hypothesized planet or can rule out its existence with a high degree of confidence.