Astronomers Discover Exoplanet With Longest Known Year

Talk about a long winter....

704 days, not years?

Jupiter takes 12 years to orbit the Sun; 704 doesn't seem especially long.

True - but we've only been finding exoplanets for a relatively short time. Depending upon the method being used in the search, a MINIMUM of two transits would be necessary to confirm the orbital period. Something with a 12 year (or longer) cycle might not have made a full orbit since its intial discovery. MOST of the exoplanets have been found within the past few years, and periods may not be known for some of them until they've completed a full circle [well, ellipse]. That could easily be several years from now.

I know; I'm an astronomer and I tend to keep up with this stuff. It just seemed funny to me that some scientist is bragging about a number that isn't particularly unusual in the larger scheme of things. Kind of like bragging you've found the tallest tree in Ohio - which would be dwarfed by a common California Redwood.

Here's a question for you or anyone willing to research this on exoplanet discoveries.

Is there a correlation between our solar system or galactic plane and the stars discovered to have planets?

If there is a correlation then that would suggest that planetary orbit planes and therefore star rotation axis may have a nominal galactic alignment.

Just some food for thought.

Interesting idea.

Imagining the gravitational influences from a galactic standpoint, and using the Solar System as a small scale model, it seems logical to assume there is a bias for planetary systems to be roughly 'co-planar' with their host galaxy.

I'd guess that for most, all we know is that the rotation plane of the exoplanet is seen roughly edge-on from our location. This means that solar systems which orbit stars "above" or "below" our depth in the Milky Way must be tipped significantly away from the main galactic plane.

"Edge-on" planes could have ANY direction for the axis perpendicular to that plane (any direction relative to our viewing direction, that is). Do a "thumbs-up" gesture: the arm represents our viewing direction, and the thumb, the perpendicular to the orbital plane. Rotate your wrist, and you can see that the arm's direction doesn't change despite a nearly 360 degree change in thumb axis direction.

Without doing much research, I'd say the answer is: unlikely.

The solar system is tipped at a fairly steep angle to the galactic equator, and thus, also tipped steeply compared to the rotation axis of the galaxy. - So there's no particular reason to think other stars with planets will have planetary orbital planes parallel to the galactic plane.

Most of the planets in our solar system lie close to the Ecliptic, the plane of the Earth's orbit. (To which the Earth itself is tipped at 23.5 degrees, which is the cause of our seasons). Here's a diagram: