New evidence for existence of Planet Nine

[seemslikeadream]

New evidence for existence of Planet Nine


A visual representation of the orbit of 2015 BP519, plotted with the other ETNOs as comparisons. For each orbit, the darker regions on the curve denote where an object falls below the plane of the solar system. 2015 BP519 has the highest …more
A large international team of researchers has found what they are describing as more evidence of the existence of Planet Nine. In their paper posted on the arXiv preprint server, the group describes the behavior of a newly discovered distant object as suggestive of an influence of a large planet.

It was just two years ago that astronomers at Caltech proposed the possible existence of a large planet circling the sun—which would make it the ninth known planet in our solar system. The researchers made their prediction based on observations of icy objects that exist at the edge of the solar system—their orbits were clearly being warped by a gravitational mass. They suggested a very distant planet roughly four times the size of Earth, but with 10 times its mass, could account for the odd behavior. If such a planet does exist, it would be quite distant, taking from 10,000 to 20,000 years to make one trip around the sun. Since announcing their initial findings, the team at Caltech has published papers offering more evidence of the planet—the possibility that it could have played a role in tilting the other planets in our solar system, for example. They have also suggested it as an explanation for why objects in the Kuiper Belt orbit in an opposite direction to everything else.

In this new effort, the researchers suggest the behavior of a certain Trans-Neptunian object could very well be due to gravity from Planet Nine. The object, called 2015 BP519 (Caju for short), was first noted approximately three years ago, but it was only recently that the shape of its orbit was found to be very unusual—it lies nearly perpendicular to the plane established by the known planets. What makes the find so compelling is that the team of researchers who first proposed the existence of Planet Nine created a simulation that predicted the orbital angle of just such an object. And it just happened to match with what has been found.

The researchers report that after Caju was first discovered, attempts were made to calculate its orbit, but they all failed. Then they added a large planet to the simulations, which resolved the discrepancies. All that is needed now, they suggest, is for someone to actually find the planet.

Explore further: In search of the ninth planet

More information: Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination, arXiv:1805.05355 [astro-ph.EP] arxiv.org/abs/1805.05355

Abstract
We report the discovery and dynamical analysis of 2015 BP519, an extreme Trans-Neptunian Object detected detected by the Dark Energy Survey at a heliocentric distance of 55 AU and absolute magnitude Hr= 4.3. The current orbit, determined from a 1110-day observational arc, has semi-major axis a≈ 450 AU, eccentricity e≈ 0.92 and inclination i≈ 54 degrees. With these orbital elements, 2015 BP519 is the most extreme TNO discovered to date, as quantified by the reduced Kozai action, which is is a conserved quantity at fixed semi-major axis a for axisymmetric perturbations. We discuss the orbital stability and evolution of this object in the context of the known Solar System, and find that 2015 BP519 displays rich dynamical behavior, including rapid diffusion in semi-major axis and more constrained variations in eccentricity and inclination. We also consider the long term orbital stability and evolutionary behavior within the context of the Planet Nine Hypothesis, and find that BP519 adds to the circumstantial evidence for the existence of this proposed new member of the Solar System, as it would represent the first member of the population of high-i, ϖ-shepherded TNOs.
https://phys.org/news/2018-05-evidence-planet.html

[DrEvil]

https://www.space.com/41995-dwarf-plane ... -nine.html

Newfound Dwarf Planet 'The Goblin' May Lead to Mysterious Planet Nine

By Mike Wall, Space.com Senior Writer | October 2, 2018 10:01am ET

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 Evidence for 'Planet Nine' in Our Solar System (Gallery)]

"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.

And 2015 TG387 is special among these bread crumbs, 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).

"And then if you bring in some of the other extreme objects — several of them were found in our survey as well," Sheppard told Space.com. "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 (8 meters) 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 (150 million kilometers). 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. [Our Solar System: A Photo Tour of the Planets]

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 (300 km) 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 told Space.com. "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.)

But going back to the orbit: The Goblin's 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 for 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 percent. And 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 told Space.com. (In case this sounds odd or incongruous: The Goblin was discovered near perihelion, at about 80 AU from the sun.)

"And 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.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

[Elvis]

Poor Pluto.