INQUISITR.COM / Science & Tech

Astronomers Find A New Dwarf Planet At The Edge Of Our Solar System

By Alexandra Lozovschi
Published on: 08:36 PST, Oct 2, 2018

In a remarkable discovery, a team of scientists led by astronomer Scott Sheppard of the Carnegie Institution for Science in Washington spotted a new dwarf planet hiding in the far reaches of our solar system, reports the Washington Post.

The announcement was made today by the Carnegie Institution for Science, which noted that the team came across this newfound dwarf planet — known as 2015 TG387 — while searching for the mysterious Planet Nine — a super-Earth 10 times bigger than our home planet believed to be lurking beyond Neptune.

Originally discovered on October 13, 2015, with the help of Japan’s Subaru telescope at Hawaii’s Mauna Kea Observatories, the dwarf planet was nicknamed “The Goblin” — “as its provisional designation contains ‘TG’ and the object was first seen near Halloween,” explains Carnegie.

However, because it moves incredibly slowly in its very elongated orbit around the sun, 2015 TG387 was confirmed as a dwarf planet only after repeated observations that lasted through May of 2018. The object was eventually announced by the International Astronomical Union’s Minor Planet Center on October 1.

This brings the number of officially recognized dwarf planets in our solar system to six. According to Space Facts, four of the other five dwarf planets — Pluto, Haumea, Makemake, and Eris (imaged above) — are also located in the outer solar system. Meanwhile, the remaining dwarf planet, Ceres, is the only one found in the inner solar system. Ceres resides in the asteroid belt between the orbits of Mars and Jupiter.

According to Sheppard, the newfound object is quite tiny even for a dwarf planet, measuring just 186 miles — or 300 kilometers — across. This puts it “on the small end of a dwarf planet,” said the astronomer. In contrast, Pluto — the largest known dwarf planet in our solar system — has a diameter of 1,473 miles (2,370 kilometers), being about two-thirds the size of Earth’s moon, notes Space.

Peculiar Orbit

The recently uncovered dwarf planet is being described as an “extremely distant object” lying “far beyond Pluto.” At the time of its discovery, 2015 TG387 was located at a distance of 80 astronomical units (AU) from the sun, where one AU is defined as the distance between Earth and the sun. One AU measures about 93 million miles.

By comparison, Pluto sits at around 34 AU. This means that 2015 TG387 was 2.5 times farther away from the sun than Pluto during its first sighting.

But “The Goblin” travels even farther out into the cosmos — and takes a whopping 40,000 years to complete a full orbit around the sun. In fact, 2015 TG387 never comes closer than 65 AU from our main star, and actually has the third-most-distant perihelion (or closest point to the sun) in the entire system, after two planetoids found in the Kuiper Belt past Neptune’s orbit: 2012 VP113 — also known as Biden (80 AU) — and Sedna (76 AU).

Interestingly enough, 2015 TG387 circles the sun on a lopsided elliptical orbit which carries it so far out from the system’s major planets that it has no chance of having “significant gravitational interactions with them.”

At its farthest point, this unusual orbit flings the dwarf planet to a staggering distance of 2,300 AU, taking it into a region of space known as the Oort Cloud — “an extended shell of icy objects that exist in the outermost reaches of the solar system” beyond the Kuiper Belt, explains Space Facts.

Clue To Planet Nine

But perhaps the most baffling thing about this newfound world is that it hints at the possibility of an even bigger object hiding out at the fringe of the solar system, namely the mysterious Planet Nine — also referred to as the missing super-Earth.

The peculiar orbit of 2015 TG387 “supports the presence of an even-farther-out, Super-Earth or larger Planet X,” stated Carnegie officials.

As the Inquisitr previously reported, Planet Nine is presumed to be located 20 times farther from the sun than Neptune — and was theorized in 2016 by Caltech planetary astrophysicists Konstantin Batygin and Mike Brown.

Its existence was first suggested by Shepard and Chad Trujillo of the Gemini Observatory in Hawaii in 2014. At the time, the pair had just published a study in the journal Nature announcing the discovery of Biden.

Just like Sedna — an icy world that circles the sun in more than 11,000 years, per a previous Inquisitr report — Biden is believed to be a member of the inner Oort Cloud and has an elongated orbit that seems to pull it away from the plane of the solar system.

The explanation for this puzzling phenomenon was attributed to the gravitational force of a massive hidden planet, the so-called Planet X, whose gravity influences the orbits of a handful of objects in the Kuiper Belt — including Sedna and Biden.

“These so-called Inner Oort Cloud objects like 2015 TG387, 2012 VP113, and Sedna are isolated from most of the solar system’s known mass, which makes them immensely interesting,” Sheppard explained. “They can be used as probes to understand what is happening at the edge of our solar system.”

‘The Goblin’ And The Gang

In a new study submitted to The Astronomical Journal and available on the preprint server arXiv, Shepard and Trujillo argue that the orbit of the newfound dwarf planet seems to be “shepherded” in the same way as those of Sedna and Biden, as well as other extremely distant objects in the Kuiper Belt. All of these objects have elongated orbits that cluster in the same part of the sky, suggesting that they could be influenced by the enigmatic Planet Nine — described as a “massive perturber” in the 2014 study.

“This clustering can only be maintained if the solar system hosts an additional, yet unseen, super-Earth type planet,” said Batygin.

The authors base their conclusion on computer simulations which showed that the orbit of 2015 TG387 is “stable for the age of the solar system” and is subject to the same type of gravitational influence that a giant planet hiding in the Kuiper Belt would exert on the smaller objects in its cosmic neighborhood.

“What makes this result really interesting is that Planet X seems to affect 2015 TG387 the same way as all the other extremely distant solar system objects. These simulations do not prove that there’s another massive planet in our Solar System, but they are further evidence that something big could be out there,” Trujillo said in a statement.

The team believes that many other worlds could be hiding out at the edge of the solar system, sharing the same orbital peculiarities as Sedna, Biden, and “The Goblin.”

“We think there could be thousands of small bodies like 2015 TG 387 out on the solar system’s fringes, but their distances make finding them very difficult,” said study co-author David Tholen of the University of Hawaii. “Currently we would only detect 2015 TG 387 when it is near its closest approach to the sun. For some 99 percent of its 40,000-year orbit, it would be too faint to see.”

Commenting of his team’s findings, Sheppard remarked that the newly detected dwarf planet is yet another piece to the puzzle that could eventually lead to the discovery of the elusive Planet Nine.

“These distant objects are like breadcrumbs leading us to Planet X. The more of them we can find, the better we can understand the outer solar system and the possible planet that we think is shaping their orbits — a discovery that would redefine our knowledge of the solar system’s evolution.”

Share this article: Astronomers Find A New Dwarf Planet At The Edge Of Our Solar System
More from Inquisitr