Talk About A Crowded Neighborhood: Closest Binary Stars With Multiple Planets Found

universetoday.com ^ | 09/02/2016 | Nancy Atkinson

[BenLurkin]

It consists of a three giant planets in a binary (two stars) system. One star hosts two planets and the other hosts the third. The system represents the smallest-separation binary in which both stars host planets that has ever been observed.

...

The twin stars are named HD 133131A and HD 133131B. The former hosts two Jupiter-sized worlds and the latter a planet with a mass at least 2.5 times Jupiter’s. All three planets have “eccentric” or highly elliptical orbits. So far no smaller, rocky worlds have been detected but the team said those type of planets could be part of the system, or may have been part of the system in the past.

The two stars themselves are separated by only 360 astronomical units (AU – the distance between the Earth and the Sun, approximately 150,000,000 km or 93,000,000 miles). This is extremely close for twin stars with detected planets orbiting the individual stars. The next-closest known binary star system with planets has stars about 1,000 AU apart.

The two stars are more like fraternal twins rather than identical because they have slight different chemical compositions. The team said this could indicate that one star swallowed some baby planets early in its life, changing its composition slightly. Or another option is that the gravitational forces of the detected giant planets may have had a strong effect on fully-formed small planets, flinging them in towards the star or out into space.

But both stars are “metal poor,” meaning that most of their mass is hydrogen and helium, as opposed to other elements like iron or oxygen. This is another curious thing about this system, as most stars that host giant planets are “metal rich.”

[Defiant]

I imagine it would be pretty unusual for a binary star system to have planets with life. You might be in a good location, getting great sunlight and have a decent climate, then along comes the other sun and fries you to death. And then, for good measure, its gravity causes rocks to start flying through the air and mountains to crumble.

I'll stick with one.

[GraceG]

[ But both stars are “metal poor,” meaning that most of their mass is hydrogen and helium, as opposed to other elements like iron or oxygen. This is another curious thing about this system, as most stars that host giant planets are “metal rich.” ]

Gas giants and Ice Giant planets can easily exist around metal poor stars...

[TheNext]

If Hillary wins ...

I am Moving to the Nearest Star System!

[minnesota_bound]

The Klingon home world was metal poor.

[SunkenCiv]

This topic was posted ages ago, thanks for posting it, thanks for reading it. I'm enjoying my end of the year check for missed topics.

· join · view topics · view or post blog · bookmark · post new topic · subscribe ·

Google news searches: exoplanet · exosolar · extrasolar ·