Astronomers discover the most distant object in the solar system: “ Farfarout ”

Astronomers have discovered the most distant object ever found in our solar system.

The planetoid – the term for a small piece of rock or dust or ice orbiting the sun – is aptly nicknamed “Farfarout”, after the previous record holder, “Farout”, which was discovered by the same astronomers in 2018. After years of observing the object’s trajectory in the sky, this team of researchers announced Wednesday that they can confidently say that Farfarout is, well, much further away than any object. of the solar system seen before.

Farfarout is 132 astronomical units (AU) from the sun, which means it is 132 times farther from the sun than Earth and about four times farther than Pluto. It takes about 1000 years for the planetoid to complete an orbit around the sun.

Researchers estimate that Farfarout is around 400 kilometers in diameter, which would put it at the bottom of the scale of a dwarf planet like Pluto.

“Farfarout’s discovery shows our increasing ability to map the outer solar system and to observe further and further towards the fringes of our solar system,” said Scott Sheppard, one of the astronomers who discovered the object, in A press release. Sheppard works as a researcher at the Carnegie Institution for Science.

Roberto Molar Candanosa, Scott S. Sheppard (Carnegie Institution for Science) and Brooks Bays (University of Hawaiʻi)

“It is only with the progress of the last few years of large digital cameras on very large telescopes that it has been possible to effectively discover very distant objects like Farfarout,” he added. “Even though some of these distant objects are quite large – the size of dwarf planets – they are very small due to their extreme distances from the Sun. Farfarout is just the tip of the iceberg of solar system objects in the far distant solar system. “

Finding and studying other objects this far away could help scientists determine if there is a massive unidentified planet lurking on the outskirts of our solar system. Scientists have found clues of such a planet, often referred to as Planet Nine or Planet X, in the distant darkness. These clues come in the form of smaller objects whose orbital paths appear skewed.

However, Farfarout probably cannot contribute to this effort, as Neptune appears to have significantly altered its orbit.

An extract from a 1000-year orbit

S. Sheppard

Farfarout crosses Neptune’s path each time it loops around the sun and its orbit is elongated in an oval shape. At some point in the cycle, it gets as close to our star as 27 AU. But it also moves away from the sun up to 175 AU. Scientists believe that this strange orbit is due to Neptune’s powerful gravitational pull.

“Farfarout’s orbital dynamics can help us understand how Neptune formed and evolved, as Farfarout was likely thrown into the outer solar system by getting too close to Neptune in the distant past,” Chad Trujillo, astronomer of the Northern Arizona University, which co-discovered the new object, said in the statement. “Farfarout will likely interact with Neptune again in the future since their orbits still intersect.”

The Subaru Telescope, located atop Maunakea in Hawaii, first spotted the planetoid in January 2018.

“All we knew was that the object appeared to be very far away when it was discovered,” Sheppard said.

It took years of observation to realize how far it was. Because Farfarout takes so long to orbit the sun, it moves very slowly across the sky. Astronomers had to observe it for years in order to obtain enough data to calculate its trajectory.

The Minor Planet Center of the International Astronomical Union officially designated Farfarout as the “2018 AG37” object on Wednesday. The planetoid will receive a more official name later, after new observations have allowed scientists to smooth out its precise orbital path.