Astronomers spot most distant object in the solar system, could point to other rogue planets

[muriel_volestrangler]

Astronomers have found the most distant object ever in our solar system, three times farther away than Pluto. The dwarf planet, which has been designated V774104, is between 500 and 1000 kilometers across. It will take another year before scientists pin down its orbit, but it could end up joining an emerging class of extreme solar system objects whose strange orbits point to the hypothetical influence of rogue planets or nearby stars.

“We can’t explain these objects’ orbits from what we know about the solar system,” says Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C., who announced the discovery here today at a meeting of the American Astronomical Society. V774104 currently sits 15.4 billion kilometers from the sun, or 103 astronomical units (AU) away. One AU is the distance between Earth and the sun.

The dwarf planet could eventually join one of two clubs. If its orbit one day takes it closer to our sun, it would become part of a more common population of icy worlds whose orbits can be explained by gravitational interactions with Neptune. But if its orbit never brings it close to the sun, it could join a rare club with two other worlds, Sedna and 2012 VP113.

These two dwarf planets never come within 50 AU of the sun, and their orbits swing as far out as 1000 AU. Sheppard calls them “inner Oort cloud objects” to distinguish them from icy Kuiper Belt objects, which reside between 30 and 50 AU. The Oort cloud is a hypothetical, thinly populated sphere of icy bodies, thousands of AU away, that marks the edge of the solar system and the end of the sun’s gravitational influence.

http://news.sciencemag.org/space/2015/11/astronomers-spot-most-distant-object-solar-system-could-point-other-rogue-planets

I'm not that happy about the language use in this article on it, and others. It hasn't been declared a 'dwarf planet' yet. As Wikipedia says, Vesta is about 500km across, and is not a dwarf planet, because it's not spherical enough. There are several other transneptunian objects between 500 and 1000km across that have not yet been declared as dwarf planets in that list. And 'rogue planet' is just sci-fi nonsense - they just mean "an unknown planet". But, anyway, it is the farthest solar system object yet seen (though Voyager 1 is about 30% farther out, by now).

[Wilms]

1. Thanks for the post AND your comments.

[tavernier]

2. What a lovely adventure for the imagination.

This is my idea of "Dancing With the Stars".

Thanks!🌠

[eppur_se_muova]

3. Actually, "rogue planet" means a planet not associated with a star.

Recent discoveries suggest that these are actually quite numerous; they were once considered hypothetical only.

Note that "other stars" and "rogue planets" are mentioned in the same context -- as possible outside influences on the orbits of solar system bodies.

https://en.wikipedia.org/wiki/Rogue_planet

[muriel_volestrangler]

5. I didn't know that, though their use of 'other rogue planets' in the headline may imply

that the headline writer didn't, either - because no rogue planet has yet been discovered that ever had something to do with the solar system. Yes, they mention rogue planets along with other stars, but later say "possible explanations include an unseen giant planet that still orbits in the deep or one that was ejected from the solar system, disturbing inner Oort cloud objects on its way out." An ejected planet fits the 'rogue' definition, I suppose, but not one still orbiting.

But thanks for the definition.

[Thor_MN]

4. Didn't the Voyager Probes technically cease to become "Solar Sysyem objects"

when they exceeded escape velocity in their gas planet slingshots? They certainly originated in the solar system, but they were essentially gone when the gravity boosts accelerated them past the velocity needed to leave the sun.