User:Nrco0e/Notes/Rings of Haumea

Animation of Haumea with its ring

The minor planet and centaur 10199 Chariklo, with a diameter of about 250 kilometres (160 mi), is the smallest celestial object with confirmed rings and the fifth ringed celestial object discovered in the Solar System, after the gas giants and ice giants. Orbiting Chariklo is a bright ring system consisting of two narrow and dense bands, 6–7 km (4 mi) and 2–4 km (2 mi) wide, separated by a gap of 9 kilometres (6 mi). The rings orbit at distances of about 400 kilometres (250 mi) from the centre of Chariklo, a thousandth the distance between Earth and the Moon. The discovery was made by a team of astronomers using ten telescopes at various locations in Argentina, Brazil, and Chile in South America during observation of a stellar occultation on 3 June 2013, and was announced on 26 March 2014.

The existence of a ring system around a minor planet was unexpected because it had been thought that rings could only be stable around much more massive bodies. Ring systems around minor bodies had not previously been discovered despite the search for them through direct imaging and stellar occultation techniques. Chariklo's rings should disperse over a period of at most a few million years, so either they are very young, or they are actively contained by shepherd moons with a mass comparable to that of the rings. The team nicknamed the rings Oiapoque (the inner, more substantial ring) and Chuí (the outer ring), after the two rivers that form the northern and southern coastal borders of Brazil. A request for formal names will be submitted to the IAU at a later date.

Discovery

Occultation

Origin

Formation of Haumea and its collisional history

Properties

Orientation, composition, brightness, opacity

The orientation of the rings is consistent with an edge-on view from Earth in 2008, explaining the observed dimming of Chariklo between 1997 and 2008 by a factor of 1.75, as well as the gradual disappearance of water ice and other materials from its spectrum as the observed surface area of the rings decreased. Also consistent with this edge-on orientation is that since 2008, the Chariklo system has increased in brightness by a factor of 1.5 again, and the infrared water-ice spectral features have reappeared. This suggests that the rings are composed at least partially of water ice. An icy ring composition is also consistent with the expected density of a disrupted body within Chariklo's Roche limit.

Rings of Chariklo

Name	Nickname	Orbital radius (km)	Width (km)	Optical depth	Surface density (g/cm2)	Size-equivalent mass	Gap between rings (km)	Radial separation (km)
2013C1R	Oiapoque	390.6±3.3	6.16±0.11 to 7.17±0.14	0.449±0.009 to 0.317±0.008	30–100	icy body ~1 km in diameter	8.7±0.4	14.2±0.2
2013C2R	Chuí	404.8±3.3	3.4+1.3 −2.0 to 3.6+1.1 −1.4	0.05+0.06 −0.01 to 0.07+0.05 −0.03	?	icy body ~0.5 km in diameter

Dynamics

Orbit, resonances, eccentricity and inclination, precession and influence by Haumea's moons

Telescopes and observatories

...

Haumea resources

The dynamics of rings around Centaurs and Trans-Neptunian objects, The Trans-Neptunian Solar System by Sicardy et al. (2020)

Discovery

• Astronomy: Ring detected around a dwarf planet, Sickafoose (2017)
  • Planetary Society-funded telescopes help find ring around Haumea, a distant dwarf planet, Davis (2017)
  • Ring around a dwarf planet detected, Muller (2017)
• The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation, Ortiz et al. (2017)

Properties

• The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation, Ortiz et al. (2017)
• Haumea's thermal emission revisited in the light of the occultation results, Müller et al. (2019)
  • Minimal near-infrared flux contributed by the ring

Orientation

• Determination of the body of the dwarf planet Haumea from observations of a stellar occultation and photometry data, Kondratyev & Kornoukov (2018)

Dynamics

• The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation, Ortiz et al. (2017)
• Dynamics of Haumea's dust ring, Kovács & Regály (2018)
• On the location of the ring around the dwarf planet Haumea, Winter et al. (2019)
• Ring dynamics around non-axisymmetric bodies with application to Chariklo and Haumea, Sicardy et al. (2019)
  • "Our model predicts that the inner part of the disk may be deposited on the equator of the body, forming a ridge akin to that of the Saturnian satellite Iapetus."
• Perturbation Maps and the ring of Haumea, Sanchez et al. (2020)
  • Stable regions within the initial resonant angles $\theta _{\rm {res}}={\rm {0}}$ and $\theta _{\rm {res}}={\rm {270}}$ for the 1:3 resonance (2,296.3955 km) are not continuous, suggesting possible gaps and structures in the ring [system].
  • Ring particles can be ejected into larger orbits beyond the Haumea-Namaka instability region, either entering a temporary co-orbital configuration or colliding with the moon.

Precession

• Secular Evolution of Rings around Rotating Triaxial Gravitating Bodies, Kondratyev & Kornoukov (2020)
  • Retrograde nodal precession period of 12.9±0.7 days and prograde apsidal precession period of ≈8.08 days.

External effects

• Ring dynamics around an oblate body with an inclined satellite: The case of Haumea, Marzari (2020)

Origin

• N-body Simulations of the Ring Formation Process around the Dwarf Planet Haumea, Sumida et al. (2020)
  • Ring formation scenario involving rotationally-fissioned fragments from Haumea that became tidally disrupted within Haumea's Roche radius
  • Due to Haumea's fast rotation and non-axisymmetric gravitational field, the orbit instability region lies within the Roche radius.