Year: 2019
Type: article
Abstract: Inner Oort cloud objects (IOCs) are trans-Plutonian for their entire orbits. They are beyond the strong gravitational influences of the known planets, yet close enough to the Sun that outside forces are minimal. Here we report the discovery of the third known IOC after Sedna and 2012 VP113, called 2015 TG387. This object has a perihelion of 65 ± 1 au and semimajor axis of 1170 ± 70 au. The longitude of perihelion angle, , for 2015 TG387 is between that of Sedna and 2012 VP113 and thus similar to the main group of clustered extreme trans-Neptunian objects (ETNOs), which may be shepherded into similar orbital angles by an unknown massive distant planet called Planet X, or Planet Nine. The orbit of 2015 TG387 is stable over the age of the solar system from the known planets and Galactic tide. When including outside stellar encounters over 4 Gyr, 2015 TG387's orbit is usually stable, but its dynamical evolution depends on the stellar encounter scenarios used. Surprisingly, when including a massive Planet X beyond a few hundred au on an eccentric orbit that is antialigned in longitude of perihelion with most of the known ETNOs, we find that 2015 TG387 is typically stable for Planet X orbits that render the other ETNOs stable as well. Notably, 2015 TG387's argument of perihelion is constrained, and its longitude of perihelion librates about 180° from Planet X’s longitude of perihelion, keeping 2015 TG387 antialigned with Planet X over the age of the solar system.
Source: The Astronomical Journal
Language: English
Topic: Astro and Planetary Science
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, University of Pennsylvania, Ohio State University, University of Oklahoma, University of Portsmouth, University College London, University of Sussex, Deutsche Forschungsgemeinschaft, Financiadora de Estudos e Projetos, National Astronomical Observatory of Japan, University of Illinois at Urbana-Champaign, Supercomputing Center for Education and Research, University of Oklahoma, Science and Technology Facilities Council, Argonne National Laboratory, Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory
Awards: THIS PROPOSAL AIMS TO DEVELOP ADDITIONAL CONSTRAINTS ON THE TIMING OF THE GIANT PLANET INSTABILITY CONDITIONS IN THE PRIMORDIAL KUIPER BELT PRIOR TO THIS AND REASSESS THE DYNAMICAL LIFETIMES OF KUIPER BELT BINARY OBJECTS. THESE GOALS WILL BE ACCOMPLISHED THROUGH THREE RESEARCH TASKS FOCUSED ON DYNAMICAL AND COLLISIONAL MODELING. FIRST WE WILL USE DYNAMICAL MODELS TO REASSESS WHETHER ULTRA-WIDE KUIPER BELT BINARIES CAN IN FACT SURVIVE FOR THE AGE OF THE SOLAR SYSTEM AND BY EXTENSION WHETHER THEIR MODERN EXISTENCE OFFERS ROBUST CONSTRAINTS ON THE EARLY SOLAR SYSTEM. SECOND WE WILL USE A COLLISIONAL AND ORBITAL SIMULATION CODE TO MODEL ACCRETION FRAGMENTATION AND THE TIME EVOLUTION OF THE OVERALL KUIPER BELT SIZE DISTRIBUTION WITHIN A MASSIVE PRIMORDIAL DISK TO DETERMINE THE TIME REQUIRED TO GENERATE THE KUIPER BELT SIZE DISTRIBUTION AND 1000+ PLUTO-SIZED OBJECTS AS A FUNCTION OF INITIAL CONDITIONS. FINALLY WE WILL STUDY HOW LONG PRIMORDIAL KBO BINARIES CAN SURVIVE WITHIN THE MASSIVE PRE-INSTABILITY KUIPER BELT AS IT GROWS AND WHETHER CONDITIONS IN THE PRIMORDIAL BELT CAN EXPLAIN THE RARITY OF EQUAL-MASS BINARIES OUTSIDE OF THE COLD CLASSICAL KUIPER BELT. THIS PROPOSED WORK WILL CLEARLY ADVANCE THE EMERGING WORLDS PROGRAM'S LARGER GOAL OF UNDERSTANDING THE FORMATION AND EARLY EVOLUTION OF THE SOLAR SYSTEM., G5834777675
OpenAlex ID: W2918029340