Friday, 18 January, 2019

Farout! Astronomers identify the most distant known object in our solar system

Farout: astronomers identify most distant known object in solar system Discovered: The most-distant solar system object ever observed
Theresa Hayes | 18 December, 2018, 16:39

Solar System distances to scale showing the newly discovered 2018 VG18 "Farout" compared to other known Solar System objects. The previous record-holder was the dwarf planet Eris at 96 astronomical units (AU). "Farout" is located at approximately 120 astronomical units (AU).

However, the team said they did not yet know enough about Farout to tell whether it was being influenced by the putative Planet X.

"I said 'far out!' when I discovered it, and it's a very far out object", said astronomer Scott Shepard from the Carnegie Institution for Science, as quoted by New Scientist.

Farout is - as its name suggests - is extremely distant from the Sun. "The orbital similarities shown by numerous known small, distant Solar System bodies was the catalyst for our original assertion that there is a distant, massive planet at several hundred AU shepherding these smaller objects".

The discovery team nicknamed the object "Farout", and its provisional designation from the International Astronomical Union is 2018 VG18.

"It is the slowest-moving object I have ever seen and is really out there".

The orbits of several known outer solar system objects, shown skewed to the left of the above image, reveal the possible existence of a larger planet (perhaps a super-Earth) with an orbit on the other side of the solar system. Farout is so far out that light from the Sun takes 16 hours and 40 minutes to travel the 11-billion-mile (18-billion-kilometer) distance.

It is an estimated 310 miles (500 kilometres) across and believed to be round.

"The orbital similarities shown by numerous known small, distant Solar System bodies was the catalyst for our original assertion that there is a distant, massive planet at several hundred AU (Astronomic Units - the distance between Earth and the Sun) shepherding these smaller objects", said Sheppard. Credit: Roberto Molar Candanosa/Scott S. Sheppard/Carnegie Institution for Science.

Discovery image of 2018 VG18 "Farout" from the Subaru Telescope on November 10, 2018.

On November 10, 2018, images captured by astronomers Scott S. Sheppard, from the Carnegie Institution for Science, and David Tholen, from the University of Hawaii, using the Subaru Telescope atop Hawaii's Mauna Kea volcano, were found to have an object that was moving against the backdrop of stars. (It takes multiple nights of observing to accurately determine an object's distance.) 2018 VG18 was seen for the second time in early December at the Magellan telescope at Carnegie's Las Campanas Observatory in Chile. Its brightness revealed that it's approximately 500km in diameter, making it a dwarf planet.

Its pink shade indicates an ice-rich object.

"This discovery is truly an worldwide achievement in research using telescopes located in Hawaii and Chile, operated by Japan, as well as by a consortium of research institutions and universities in the United States", Trujillo said in the press release.

"With new wide-field digital cameras on some of the world's largest telescopes, we are finally exploring our solar system's fringes far beyond Pluto", he said.

It'll be a while before astronomers determine Farout's orbit. "Planet X is also likely even further away, at a few hundred AU". The Kuiper belt ends at a distance of about 50 astronomical units, and the space beyond that was thought to be largely empty.