A Dwarf Planet Class Object in the 21:5 Resonance with Neptune

Abstract

We report the discovery of a H r = 3.4 ± 0.1 dwarf planet candidate by the Pan-STARRS Outer Solar System Survey. 2010 JO 179 is red with (g − r) = 0.88 ± 0.21, roughly round, and slowly rotating, with a period of 30.6 hr. Estimates of its albedo imply a diameter of 600-900 km. Observations sampling the span between 2005-2016 provide an exceptionally well-determined orbit for 2010 JO 179 , with a semi-major axis of 78.307 ± 0.009 au; distant orbits known to this precision are rare. We find that 2010 JO 179 librates securely within the 21:5 mean-motion resonance with Neptune on hundred-megayear time scales, joining the small but growing set of known distant dwarf planets on metastable resonant orbits. These imply a substantial trans-Neptunian population that shifts between stability in high-order resonances, the detached population, and the eroding population of the scattering disk.

A Pluto–Charon Sonata: Dynamical Limits on the Masses of the Small Satellites

“…The internal structure of the asteroid belt and the small mass of Mars constrain the formation of Jupiter and the disappearance of the protosolar nebula (e.g., Walsh et al 2011;Izidoro et al 2014;Brasser et al 2016;Bromley & Kenyon 2017;Clement et al 2019). Different classes of Kuiper belt objects just beyond the orbit of Neptune hold traces of the early orbital evolution of the gas giant planets (r.g., Malhotra 1993;Ida et al 2000;Levison & Morbidelli 2003;Gomes et al 2004;Tsiganis et al 2005;Dawson & Murray-Clay 2012;Holman et al 2018). Sedna and other transneptunian objects may point to a ninth planet orbiting the Sun at distances more than ten times beyond the orbit of Neptune (Trujillo & Sheppard 2014;Sheppard & Trujillo 2016;Becker et al 2018;Sheppard et al 2018;Brown & Batygin 2019).…”

Trans-Neptunian Objects Transiently Stuck in Neptune’s Mean-motion Resonances: Numerical Simulations of the Current Population

“…Because this transient sticking rarely produces objects that are tightly bound within resonances, it is not thought to be the primary production mechanism for the most studied populations of resonant TNOs: those in the 3:2 and 2:1 resonances. However, the recent confirmation of an unexpectedly large population of 5:2 resonant objects (Gladman et al 2012;Volk et al 2016), as well as the detection of objects known to be transient members of Neptune's distant resonances (Bannister et al 2016a;Holman et al 2018), brings new urgency to the characterization of the transiently stuck population.…”

A Northern Ecliptic Survey for Solar System Science

“…There are no hard cutoffs, but there is an overall preference for visits to be as deep as possible without sacrificing sky coverage. Past wide-field Solar System surveys have reached a limiting magnitude of ∼22nd mag in R (e.g Schwamb et al 2010;Chambers et al 2016;Holman et al 2018). Thus for LSST to make a significant contribution to Solar System Science, the 5-σ limiting magnitude per exposure in r and g must be greater than 23rd magnitude with exposure times of 30s or more.…”

“…We note that several members of the SSSC have written versions of a slow moving object pipeline (e.g. Brown et al 2004;Schwamb et al 2010;Sheppard & Trujillo 2016;Bannister et al 2017;Gerdes et al 2017;Holman et al 2018) for other outer Solar System surveys and have the expertise to develop such a community pipeline. We also note that this pipeline could reasonably work on the sources generated from individual images, rather than requiring the image pixels directly, and can further reject a large majority of the sources in each individual image immediately as correlated with (long-term) stationary objects; the relevant inputs are relatively small compared to LSST data processing.…”