Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userOn the rotation of co-orbital bodies in eccentric orbits
96
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We investigate the resonant rotation of co-orbital bodies in eccentric and planar orbits. We develop a simple analytical model to study the impact of the eccentricity and orbital perturbations on the spin dynamics. This model is relevant in the entire domain of horseshoe and tadpole orbit, for moderate eccentricities. We show that there are three different families of spin-orbit resonances, one depending on the eccentricity, one depending on the orbital libration frequency, and another depending on the pericenters dynamics. We can estimate the width and the location of the different resonant islands in the phase space, predicting which are the more likely to capture the spin of the rotating body. In some regions of the phase space the resonant islands may overlap, giving rise to chaotic rotation.
rate research
Read More
We study the phase space of eccentric coplanar co-orbitals in the non-restricted case. Departing from the quasi-circular case, we describe the evolution of the phase space as the eccentricities increase. We find that over a given value of the eccentricity, around $0.5$ for equal mass co-orbitals, important topological changes occur in the phase space. These changes lead to the emergence of new co-orbital configurations and open a continuous path between the previously distinct trojan domains near the $L_4$ and $L_5$ eccentric Lagrangian equilibria. These topological changes are shown to be linked with the reconnection of families of quasi-periodic orbits of non-maximal dimension.
We investigate the properties of the hydrodynamic flow around eccentric protoplanets and compare them with the often assumed case of a circular orbit. To this end, we perform a set of 3D hydrodynamic simulations of protoplanets with small eccentricities ($eleq 0.1$). We adopt an isothermal equation of state and concentrate resolution on the protoplanet to investigate flows down to the scale of the protoplanets circumplanetary disk (CPD). We find enhanced prograde rotation exterior to the CPD for low planet masses undergoing subsonic eccentric motion. If the eccentricity is made large enough to develop a bow shock, this trend reverses and rotation becomes increasingly retrograde. The instantaneous eccentric flow field is dramatically altered compared to circular orbits. Whereas the latter exhibit a generic pattern of polar inflow and midplane outflow, the flow geometry depends on orbital phase in the eccentric case. For even the modest eccentricities tested here, the dominant source of inflow can come from the midplane instead of the poles. We find that the amount of inflow and outflow increases for higher $e$ and lower protoplanet masses, thereby recycling more gas through the planets Bondi radius. These increased fluxes may increase the pebble accretion rate for eccentric planets up to several times that of the circular orbit rate. In response to eccentric motion, the structure and rotation of the planets bound CPD remains unchanged. Because the CPD regulates the eventual accretion of gas onto the planet, we predict little change to the gas accretion rates between eccentric and circular planets.
An episode of dynamical instability is thought to have sculpted the orbital structure of the outer solar system. When modeling this instability, a key constraint comes from Jupiters fifth eccentric mode (quantified by its amplitude M55), which is an important driver of the solar systems secular evolution. Starting from commonly-assumed near-circular orbits, the present-day giant planets architecture lies at the limit of numerically generated systems, and M55 is rarely excited to its true value. Here we perform a dynamical analysis of a large batch of artificially triggered instabilities, and test a variety of configurations for the giant planets primordial orbits. In addition to more standard setups, and motivated by the results of modern hydrodynamical simulations of the giant planets evolution within the primordial gaseous disk, we consider the possibility that Jupiter and Saturn emerged from the nebular gas locked in 2:1 resonance with non-zero eccentricities. We show that, in such a scenario, the modern Jupiter-Saturn system represents a typical simulation outcome, and M55 is commonly matched. Furthermore, we show that Uranus and Neptunes final orbits are determined by a combination of the mass in the primordial Kuiper belt and that of an ejected ice giant.
We present the results of a search for occultation events by objects at distances between 100 and 1000 AU in lightcurves from the Taiwanese-American Occultation Survey (TAOS). We searched for consecutive, shallow flux reductions in the stellar lightcurves obtained by our survey between 7 February 2005 and 31 December 2006 with a total of $sim4.5times10^{9}$ three-telescope simultaneous photometric measurements. No events were detected, allowing us to set upper limits on the number density as a function of size and distance of objects in Sedna-like orbits, using simple models.
We report the discovery of two short-period massive giant planets from NASAs Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30-minute cadence Full Frame Images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESSs Follow-up Observing Program Working Group. We find that TOI-558 b, which transits an F-dwarf ($M_{star}=1.349^{+0.064}_{-0.065} M_{odot}$, $R_{star}=1.496^{+0.042}_{-0.040} R_{odot}$, $T_{eff}=6466^{+95}_{-93}$ K, age $1.79^{+0.91}_{-0.73}$ Gyr) with an orbital period of 14.574 days, has a mass of $3.61pm0.15 M_J$, a radius of $1.086^{+0.041}_{-0.038} R_J$, and an eccentric (e=$0.300^{+0.022}_{-0.020}$) orbit. TOI-559 b transits a G-dwarf ($M_{star}=1.026pm0.057 M_{odot}$, $R_{star}=1.233^{+0.028}_{-0.026} R_{odot}$, $T_{eff}=5925^{+85}_{-76}$ K, age $1.79^{+0.91}_{-0.73}$ Gyr) in an eccentric (e=$0.151pm0.011$) 6.984-day orbit with a mass of $6.01^{+0.24}_{-0.23} M_J$ and a radius of $1.091^{+0.028}_{-0.025} R_J$. Our spectroscopic follow-up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive ($>3 M_J$), adding to the population of massive hot Jupiters identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
