MLO 4 System

MLO 4 is most commonly known as Gliese 667 and also known as HR 6426 and HD 156384. A triple star system 23 light years away that contains planets in Scorpius. It was first cataloged as a binary star by astronomers at the old Melbourne Observatory (MLO) in Australia in 1867, so it was cataloged as MLO 4. It consisting of binary of orange dwarf stars about 12 AU apart (ranging from 5 to 20 AU), around which a distant red Dwarf C orbits (ranging from 56 to 215 AU). Star C is a dynamically packed planetary system, with at up to 7 unconfirmed super-Earth planets. The system became the nearest multistar system with planets when planet b (innermost, largest), a temperate super Earth planet (5.7 ME, 0.05 AU) was discovered, and is at the very inner edge of the most generous habitable zone. It became the poster child for an announcement of 32 exoplanets discovered by European astronomers working on the HARPs project and brought the total number of exoplanets to near 400. Planet c was later discovered near the inner edge of least generous habitable zone and is about the same size, and receives the same amount of stellar energy as the Earth. It was calculated that it likely no longer has a magnetic field that could protect its oceans from stellar radiation. Planets f and e were confirmed and also orbit in the Hz further out. Planet d is just beyond he HZ. Outermost planet, g (2.4 ME) is likely a frozen planet and the only one beyond Mercury-like distances. The multi-planet solution is somewhat lax and complicated and may need further confirmation. An even more unconfirmed planet h may be between b and c. A fourth stellar companion D is not gravitationally bound to the system.

Gliese 667 System Web Pages[]

Gliese 667 System In the News[]

32 New Exoplanets Discovered (Oct 2009)[]

Planet c Found in Habitable Zone (Feb 2012)[]

Planet c Confirmed (in Hz) (Apr 2012)[]

More Possible Planets (Dec 2012)[]

http://arxiv.org/abs/1212.4058

More Planets, 3 in HZ? (Jun 2013)[]

Magnetic Field Probably Not Strong Enough to Protect Oceans[]

http://www.newscientist.com/article/dn23393-magnetic-death-leaves-earthlike-exoplanets-dried-out.html#.UtGqObSMKSo

Recap (Dec 20013)[]

http://www.astrobio.net/exclusive/5840/the-state-of-super-earths