Curious Tilt of the Sun Traced To Undiscovered Planet (spacedaily.com)

An anonymous reader writes: Planet Nine - the undiscovered planet at the edge of the solar system that was predicted by the work of Caltech's Konstantin Batygin and Mike Brown in January 2016 -- appears to be responsible for the unusual tilt of the Sun, according to a new study. The large and distant planet may be adding a wobble to the solar system, giving the appearance that the Sun is tilted slightly. "Because Planet Nine is so massive and has an orbit tilted compared to the other planets, the solar system has no choice but to slowly twist out of alignment," says Elizabeth Bailey, a graduate student at Caltech and lead author of a study announcing the discovery. All of the planets orbit in a flat plane with respect to the Sun, roughly within a couple degrees of each other. That plane, however, rotates at a six-degree tilt with respect to the Sun -- giving the appearance that the Sun itself is cocked off at an angle. Until now, no one had found a compelling explanation to produce such an effect. "It's such a deep-rooted mystery and so difficult to explain that people just don't talk about it," says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy.

Comments

Just curious...

[XxtraLarGe]

How is it that we have an undiscovered planet in our solar system, yet we're able to find earth-like planets orbiting stars that are light-years away?

Say this aloud: "It's so massive..."

[starglider29a]

"How massive is it?"
"It's so massive that even at an insane distance, this Oort Cloud body can out-twist the masses of both Jupiter AND Saturn."

Wait? How massive is it? How is it able to tilt the axis of the sun, since tilting an axis is a TIDAL action? IMHO (as a degreed rocket scientist) that Occam's Razor would indicate that it's easier to shift the orbital planes of the planets, rather than tidally torque the sun. Remember, for the tidal action, the Planet IX must be very close to Sol to work its magic.

Re:Say this aloud: "It's so massive..."

[mysticgoat]

A more careful reading of the article reveals that what is being tilted is the plane of the ecliptic. From a geocentric point of view, that appears to be a tilt of the Sun's axis, but to an observer outside the solar system, it is the plane of the orbits of all the known "non-dwarf" planets that is tilted. (IIRC, Pluto's orbit is outside the plane of the ecliptic-- which is part of the reason it took so long to find it after the maths showed it must exist.)

Do we have enough data to estimate the orbital period of Planet IX? If so, it may be possible to correlate its changing angle to the plane of the ecliptic with long term changes in Earth climates. It would seem that during the thousands of years when Planet IX is near the plane of the ecliptic, the Earth's orbit would become more oval. Currently Earth is closest to the Sun (and moving faster in its orbit) around January 3, give or take a day; and most distant around July 3 (moving most slowly in its orbit). This causes Summer in the northern hemisphere to be around 4 days longer than Summer in the southern hemisphere. If Planet IX can cause a tilt of the planetary orbits at this time, then when it is in line with the plane of the ecliptic the Earth should see northern Summers significantly longer than southern Summers (and southern Winters longer than northern Winters).