Widest Planet System comprising of lonely planet 2MASS J2126 and its distant star TYC 9486-927-1 discovered


Who: A lonely planet named 2MASS J2126
What: Discovered by a team of astronomers of UK, USA and Australia
When: Published on 26 January 2016

A team of astronomers of UK, USA and Australia discovered the widest planet system so far comprising of lonely planet named 2MASS J2126 in a huge orbit around its star TYC 9486-927-1. The discovery was published in Monthly Notices of the Royal Astronomical Society on 26 January 2016.

Key Characteristic of 2MASS J2126

• The planet 2MASS J2126 is about 1 trillion (1 million million) kilometres from its parent star, or about 7000 times the distance from the Earth to the Sun.

• It takes roughly 900000 years for the planet to complete one revolution of the parent star.

• TYC 9486-927-1 and 2MASS J2126 are moving through space together and are both about 104 light years from the Sun.

• The planet discovered in an infrared sky survey is a possible member of a 45 million year old group of stars and brown dwarfs known as the Tucana Horologium Association.

• Based on estimated age, the mass of 2MASS J2126 would be between 11.6 to 15 times the mass of Jupiter. This placed it on the boundary between planets and brown dwarfs.

• It has a similar mass, age and temperature to one of the first planets directly imaged around another star, beta Pictoris b but unlike Pictoris b is more than 700 times further away from its host star.


In the last five years a number of free floating planets have been found but these were gas giant worlds like Jupiter as they all lacked the mass for the nuclear reactions that make stars shine, so cool and fade over time.

Measuring the temperatures of these objects is relatively straightforward, but it depends on both mass and age. This means astronomers need to find out how old they are, before they can find out if they are lightweight enough to be planets or if they are heavier ‘failed stars’ known as brown dwarfs.