Brazilian scientists investigate dwarf planet’s ring

Publicado em 15 maio 2019

Found in 2004, Haumea is a dwarf planet positioned past Pluto’s orbit in a area of the Photo voltaic System referred to as the Kuiper Belt. Pluto was demoted from the class of absolutely fledged planets in 2006 due to the invention of Haumea and different dwarf planets.

Haumea was formally acknowledged as a dwarf planet in 2008. Its ellipsoidal form resembles that of the ball utilized in rugby or American soccer. It has two moons and a hoop. Due to its ring, Haumea is a member of a gaggle of Photo voltaic System objects comprising the planets Saturn, Uranus, Neptune and Jupiter, in addition to the asteroids Chariklo and Chiron, which orbit between Jupiter and Neptune.

Haumea’s ring has by no means been instantly noticed. Its existence was inferred in 2017 by a world group of astronomers who took detailed measurements of the sunshine fluctuations as Haumea occulted (handed in entrance of) a star. In house, an occultation happens when one object passes in entrance of one other from an observer’s perspective.

“The sunshine from the star was noticed from Earth because the star was occulted by Haumea. Its brightness decreased as Haumea handed in entrance of it, enabling the astronomers to acquire details about Haumea’s form,” mentioned Othon Cabo Winter, Full Professor at São Paulo State College’s Engineering College (FE-UNESP) in Guaratinguetá, Brazil.

“The star’s gentle additionally light when the ring handed in entrance of it, enabling them to acquire info on the ring as effectively.”

The researchers who found the ring in 2017 urged that its orbit round Haumea was very near the 1:three resonance area, that means that ring particles make one revolution each 3 times Haumea rotates.

A brand new examine by Winter, Taís Ribeiro and Gabriel Borderes Motta, who belong to UNESP’s Orbital Dynamics and Planetology Group, reveals {that a} diploma of eccentricity could be required for this resonance to behave on the ring particles.

Based on Winter, the truth that the ring is slender and virtually round prevents motion by the resonance. Nevertheless, the group recognized a selected kind of secure, virtually round, periodic orbit in the identical area as Haumea’s ring. A periodic orbit is an orbit that repeats over time.

“Our examine is not observational. We didn’t instantly observe the ring. Nobody ever has,” Winter mentioned. The reason being that the ring may be very tenuous and far too far-flung to be seen by the astronomic observatories right here on Earth. The typical distance between Haumea and the Solar is 43 instances the space between Earth and the Solar.

“Our examine is solely computational. Primarily based on simulations utilizing the out there knowledge on Haumea and the ring, topic to Newton’s regulation of gravitation, which describes the motions of the planets, we concluded that the ring is not in that area of house owing to the 1:three resonance however owing to a household of secure periodic orbits,” Winter mentioned.

In an article revealed in Month-to-month Notices of the Royal Astronomical Society, the researchers discover the dynamics of particular person particles within the area the place the ring is positioned.

The analysis behind the paper was a part of the Thematic Venture “On the relevance of small our bodies in orbital dynamics” funded by São Paulo Analysis Basis – FAPESP and supported by the Brazilian federal authorities through CAPES, the upper schooling analysis council, and CNPq, the Nationwide Council for Scientific and Technological Improvement.

“The primary purpose of our analysis was to establish the construction of Haumea’s ring by way of the situation and dimension of the secure areas. We additionally wished to search out the rationale for the ring’s existence. We have been notably concerned with attempting to grasp the dynamic construction related to its 1:three resonance,” Winter mentioned.

Secure areas

The researchers used the Poincaré surface-of-section approach to investigate the dynamics of the area during which the ring is positioned. By simulating the trajectories of particles within the area, they generated laptop graphics (sections) displaying secure areas represented as islands (closed curves) and unstable areas represented as irregularly distributed factors.

The islands of stability discovered to be as a result of 1:three resonance had extremely eccentric orbits, extra so than could be suitable with the ring (slender and round).

“Alternatively, we detected islands of stability in the identical space however with trajectories of low eccentricity that have been suitable with the ring. These islands have been discovered to be as a result of a household of periodic orbits,” Winter mentioned.

Haumea has a diameter of 1,456 km, lower than half the diameter of Mars, and an oval form that makes it twice so long as it’s large. It takes 284 years to go around the Solar. The dwarf planet is so far-off, and the daylight that reaches it so weak, that its floor temperature is minus 223 °C.

Haumea’s moons Namaka and Hello’iaka have been detected by the large lenses of one of many observatories atop Hawaii’s dormant volcano Mauna Kea. The dwarf planet is called for the Hawaiian goddess of fertility and childbirth, and its moons are named for Haumea’s daughters. They’re believed to have resulted from a collision between the dwarf planet and another physique.

Haumea completes a rotation in beneath 4 hours, spinning quicker than another identified equilibrium physique within the Photo voltaic System. This will should do with a violent previous.

Astronomers suppose Haumea was initially very similar to Pluto when the Photo voltaic System was shaped. Billions of years in the past, a big object might have collided with Haumea, expelling most of its floor ice and making it spin a lot quicker than the opposite dwarf planets.


About São Paulo Analysis Basis (FAPESP)

The São Paulo Analysis Basis (FAPESP) is a public establishment with the mission of supporting scientific analysis in all fields of data by awarding scholarships, fellowships and grants to investigators linked with larger schooling and analysis establishments within the State of São Paulo, Brazil. FAPESP is conscious that the easiest analysis can solely be completed by working with the perfect researchers internationally. Due to this fact, it has established partnerships with funding companies, larger schooling, personal firms, and analysis organizations in different international locations identified for the standard of their analysis and has been encouraging scientists funded by its grants to additional develop their worldwide collaboration. You possibly can study extra about FAPESP at and go to FAPESP information company at to maintain up to date with the newest scientific breakthroughs FAPESP helps obtain via its many applications, awards and analysis facilities. You might also subscribe to FAPESP information company at

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