The Universe plays snooker too

Astronomers from the University of Warwick and the University of Sheffield have discovered a distant star system which they say resembles a game of snooker.

The scientists say the unusual constellation looks like a snooker game, with the white cue ball, one red ball and two coloured balls.

NN Serpentis is a ‘binary star system’ consisting of two stars – a red dwarf and a white dwarf – and is 1,670 light years away from Earth. The two stars orbit each other in an unusually tight orbit, a pattern which scientists believe must be due to the presence of two giant, unseen gas planets.

“The two gas giants have different masses but they may actually be roughly the same size as each other and in fact will be roughly the same size as the red dwarf they orbit,” said Professor Tom Marsh of Warwick’s Physics Department.

“If they follow the patterns we see in our own star system of gas giants with a dominant yellow or blue colours, then it is hard to escape the image of this system as being like a giant snooker frame with a red ball, two coloured balls and a dwarf white cue ball.”

Scientists believe the larger of the two gas giants is around six times the mass of Jupiter and orbit’s the binary star every 15.5 years. The smaller planet is thought to be around 1.6 times the mass of Jupiter and have an orbit of 7.75 years.

Professor Vik Dhillon, from the University of Sheffield, says there are two possible scenarios that could have seen the birth of the planets: “If these planets were born along with their parent stars they would have had to survive a dramatic event a million years ago: when the original primary star bloated itself into a red giant, causing the secondary star to plunge down into the present very tight orbit, thereby casting off most of the original mass of the primary. Planetary orbits would have seen vast disturbances.

“Alternatively, the planets may have formed very recently from the cast off material. Either way, in relatively recent times in astronomical terms this system will have seen a vast shock to the orbits of the stars and planets, all initiated by what is now the white dwarf at the heart of the system.”

The two universities helped an international team of scientists observe the system using two decades’ worth of observations from telescopes right across the globe. They found that the larger red dwarf eclipsed the white one at three hour and seven minute intervals.

The full research paper is published in the journal ‘Astronomy and Astrophysics’.