Planet Hunters find bite-size planetary system

[Ann]

Click to view full size image

So far, Kepler has found systems with up to six planets (as shown here).
The only known system with more planets is our own.
But Planet Hunters may have found the first seven-planet system
NASA / Tim Pyle

Planet Hunters are ordinary citizens who examine the Kepler spacecraft's light curves of stars and look out for signs of transits that have not been detected by professional astronomers. Since December 2010, more than a quarter of a million volunteers have examined more than 19 million light curves, corresponding to 180 years of work! And the Planet Hunters have been successful, too: They have discovered 14 probable new planets, including one that makes its own system a seven-planet one!

The seven-planet system is amazing, just like so many other exoplanets and exo-planetary systems have turned out to be. Although the host star and proud "mother" of seven, KIC 11442793, is just a little larger and hotter than the Sun, its planetary system of planetary "kids" is fit for hobbits or liliputians, a solar system shrunk to a doll's house size! All seven planets would fit between the Earth and the Sun, even though all the planets are considerably larger than the Earth!

Read more here.

Ann

[BDanielMayfield]

It’s nice to see that humans can still find things that a super computer can miss. Well done, Planet Hunters.

It’s also wonderful to be finding rich planetary systems like this one. Just think, seven planets inside the space that in our system contains only three. If this planetary frequency applied to our solar system there would be about 18 or 19 planets out to around 30 AU! [8 major planets in our system x (7 planets out to 1 AU there / 3 planets out to 1 AU here)] Also, 30 AU is by no means the outer limit for planets; the current record may be WD 0806-661B which is listed as being in a whopping 2500 AU orbit. On the small side systems have even been found that have 5 planets that would fit inside Mercury’s orbit.

All this makes me wonder what the maximum number of planets around a star might be. My hunch would be that this number could make 8 look rather paltry in comparison.

[CygnusOB2]

The growing field of exo-planetary research is still young in comparison to its older and wiser siblings in astronomy, but new findings like this show :
firstly planetary systems are extremely diverse, and secondly : the human brain is a remarkably useful tool.
Here's a smilie from one proud citizen scientist to all the others

[rstevenson]

The only surprising thing about these planetary systems we're finding is how unsurprising they are. If anyone expected to find no planets, or to find just planetary systems like our own, they would have been foolish indeeed. Variety is expected!

Bear in mind that our own system looked very different (so we currently theorize) early in its history, with perhaps 50 to 100 planets from Moon- to Mars-sized in just the inner rocky planet zone. These early planets kept banging into each other or getting ejected from the system, while the large gaseous planets adjusted their orbits, until the system settled down to more or less what we have today. See this Wikipedia page for more info.

We may well be seeing these apparently odd systems at earlier stages of their system life, not necessarily at their mature stage.

Rob

[Ann]

The only surprising thing about these planetary systems we're finding is how unsurprising they are. If anyone expected to find no planets, or to find just planetary systems like our own, they would have been foolish indeeed. Variety is expected!

Bear in mind that our own system looked very different (so we currently theorize) early in its history, with perhaps 50 to 100 planets from Moon- to Mars-sized in just the inner rocky planet zone. These early planets kept banging into each other or getting ejected from the system, while the large gaseous planets adjusted their orbits, until the system settled down to more or less what we have today. See this Wikipedia page for more info.

We may well be seeing these apparently odd systems at earlier stages of their system life, not necessarily at their mature stage.

Rob

Very good points, Rob.

I wonder, though, how many planetary systems end up in configurations like our own? Most of them, half of them or few of them?

Of course, "few of them" might still mean millions and millions of them.

I wonder, too, how long our own present configuration is going to last.

Ah, questions, questions!

Ann