Newfound dwarf planet may lead to mysterious Planet Nine!

on . Posted in Articles of Interest

WASHINGTON (PNN) - October 2, 2018 - Scientists have discovered yet another marker on the trail toward the putative Planet Nine.

That clue is 2015 TG387, a newfound object in the far outer solar system, way beyond Pluto. The orbit of 2015 TG387 shares peculiarities with those of other extremely far flung bodies, which appear to have been shaped by the gravity of a very large object in that distant, frigid realm - the hypothesized Planet Nine, also known as Planet X.

"These distant objects are like breadcrumbs leading us to Planet X," study leader Scott Sheppard, of the Carnegie Institution for Science in Washington, D.C., said in a statement.

"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," he added.

2015 TG387 is special among these breadcrumbs, because it was found during a relatively uniform survey of the northern and southern skies rather than a targeted hunt for clustered objects in certain parts of the sky, Sheppard said. Targeted hunts can produce biased results - for example, the appearance of clustering where none may actually exist, he explained.

2015 TG387 has two dwarf-planet companions in the low-bias class, Sheppard said: 2012 VP113, which he and his colleague Chadwick Trujillo (who's a co-author of the new paper as well) spotted in 2014 as part of the same, ongoing long-term survey; and the relatively bright Sedna (because the whole sky has been searched to its level of brightness).

"Then if you bring in some of the other extreme objects - several of them were found in our survey as well," said Sheppard. "The statistics get better and better that this planet is likely out there."

Sheppard and his colleagues first spotted 2015 TG387 in October 2015, using Japan's 26-foot Subaru telescope atop the volcanic peak Mauna Kea in Hawaii. The researchers nicknamed the object "The Goblin," because of the discovery date and the "TG" in the provisional designation.

It took the team three additional years to nail down The Goblin's orbit, which they did with the aid of observations by the Las Campanas Observatory in Chile and the Discovery Channel Telescope in Arizona.

2015 TG387 loops around the sun on an extremely elliptical path, coming within about 65 astronomical units (AU) of the sun at its closest point (known as perihelion) and getting about 2,300 AU away at its most distant (aphelion).

One AU is the average Earth-sun distance - about 93 million miles. So 2015 TG387 is way, way out there. Indeed, it takes about 40,000 Earth years for the newfound object to complete one lap around the sun.

Only two known solar system bodies have more-distant perihelia than The Goblin does (2012 VP113 and Sedna), and only one (2014 FE72) has a greater aphelion distance. (For perspective, Pluto never gets closer to the sun than 29.7 AU, or farther away than 49.3 AU.)

Sheppard and his colleagues think 2015 TG387 is about 186 miles wide and probably spherical, in which case it would qualify as a dwarf planet. But that's all they can really say about The Goblin's physical characteristics.

"It's pretty faint, so we can really just see that it's there," Sheppard said. "We don't even know the color of the object; we haven't gotten any spectroscopy on the object yet, or anything like that."

(The 186-mile diameter is not a measurement but rather an estimate, assuming a "moderate" reflectiveness for 2015 TG387.)

The Goblin's orbit is similar in key ways to those of some other extremely distant bodies - particularly in an element called "longitude of perihelion". Basically, the elongated parts of their elliptical orbits are clustered in the same part of the sky, which is consistent with gravitational shepherding by Planet X.

The existence of Planet X was first seriously proposed in 2014 by Sheppard and Trujillo, to potentially explain oddities in the orbits of 2012 VP113, Sedna, and a few other trans-Neptunian objects.

In 2016, astronomers Konstantin Batygin and Mike Brown presented more evidence for such an unseen "perturber," which they called Planet Nine. Batygin and Brown have suggested that this world may be about 10 times more massive than Earth and orbit about 600 AU from the sun on average.

In the new study, the researchers also performed computer simulations to test how Planet X's gravitational tug might influence the orbit of The Goblin. They found significant shepherding akin to that inferred from other distant objects - and determined that 2015 TG387's orbit remains stable for the age of the solar system nonetheless.

"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," Trujillo, who's based at Northern Arizona University, said in the same statement. "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."

Sheppard puts the odds of Planet X's existence at around 85%. He says it's not at all surprising that astronomers haven't spotted it yet.

"Where we think the planet is - hundreds of AU away, if not 1,000 AU - something even as big as Neptune would be fainter than most telescopes could see," Sheppard said. (In case this sounds odd or incongruous, The Goblin was discovered near perihelion, at about 80 AU from the sun.)

"Most of our surveys to date do not go that faint, do not go that deep. We've covered very little of the sky to the depth that's needed to be covered to find something this faint," he added. "You can hide a very big thing in the outer solar system very easily."

The paper describing the discovery of 2015 TG387 has been submitted to The Astronomical Journal.

Eulogies

Eulogy for an Angel
1992-Dec. 20, 2005

My Father
1918-2010

brents dad

Dr. Stan Dale
1929-2007

stan dale

A. Solzhenitsyn
1918-2008

solzhenitsyn

Patrick McGoohan
1928-2009

mcgoohan

Joseph A. Stack
1956-2010

Bill Walsh
1931-2007

Walter Cronkite
1916-2009

Eustace Mullins
1923-2010

Paul Harvey
1918-2009

Don Harkins
1963-2009

Joan Veon
1949-2010

David Nolan
1943-2010

Derry Brownfield
1932-2011

Leroy Schweitzer
1938-2011

Vaclav Havel
1936-2011

Andrew Breitbart
1969-2012

Dick Clark
1929-2012

Bob Chapman
1935-2012

Ray Bradbury
1920-2012

Tommy Cryer
1949-2012

Andy Griffith
1926-2012

Phyllis Diller
1917-2012

Larry Dever
1926-2012

Brian J. Chapman
1975-2012

Annette Funnicello
1942-2012

Margaret Thatcher
1925-2012

Richie Havens
1941-2013

Jack McLamb
1944-2014

James Traficant
1941-2014

jim traficant

Dr. Stan Monteith
1929-2014

stan montieth

Leonard Nimoy
1931-2015

Leonard Nimoy

Stan Solomon
1944-2015

Stan Solomon

B. B. King
1926-2015

BB King

Irwin Schiff
1928-2015

Irwin Schiff

DAVID BOWIE
1947-2016

David Bowie

Muhammad Ali
1942-2016

Muhammed Ali

GENE WILDER
1933-2016

gene wilder

phyllis schlafly
1924-2016

phylis schafly

John Glenn
1921-2016

John Glenn

Charles Weisman
1954-2016

Charles Weisman

Carrie Fisher
1956-2016

Carrie Fisher

Debbie Reynolds
1932-2016

Debbie Reynolds

Roger Moore
1917-2017

Roger Moore

Adam West
1928-2017

Adam West

JERRY LEWIS
1926-2017

jerry lewis

HUGH HEFNER
1926-2017

Hugh Hefner

PROF. STEPHEN HAWKING
1942-2018

Hugh Hefner 

ART BELL
1945-2018

Art Bell

DWIGHT CLARK
1947-2018

dwight clark

CARL MILLER
1952-2017

Carl Miller

HARLAN ELLISON
1934-2018

Harlan Ellison

STAN LEE
1922-2018

stan lee