A new and unusual system
Sylvie Lewis discusses the discovery of a star system that breaks all the rules
A University of Wisconsin-Madison research team has discovered a giant planet orbiting around a white dwarf star. This star system appears to be violating all usual norms for stars and planets, leaving astronomers wondering how it came to be in the first place.
A white dwarf, also known as a dead star, is what remains when a sun-like star expands into a red giant. The existence of an enormous planet in a tiny white dwarf’s orbit has puzzled researchers. The Jupiter-sized planet circles the white dwarf every 34 hours. Keeping in mind Mercury’s 90-day orbit, and Earth’s 365-day orbit, this giant planet’s orbit is extremely close in comparison. This unconventional planetary system has left astronomers asking: how has this planet stayed intact?
The… planet circles the white dwarf every 34 hours
Further research was conducted, in which new star simulations were created to test the conditions of the star system. Ultimately, the researchers discovered that this unusual discovery was the result of a process spanning billions of years. The formation of this particular star system appears to have begun almost 6 billion years ago. In the simulation, at the point where the star ran out of fuel, it swelled into a red giant, causing it to engulf other nearby planets. The Jupiter-sized planet, orbiting at a distance from the star, was then destabilised. The planet developed an oval orbit, bringing it into close proximity with the white dwarf. The 6 billion year duration of this process gave the white dwarf time to slow the giant planet down.
New star simulations were created to test the conditions of the star system
Researchers have also been excited by the possibility of searching for signs of life in this system by studying its chemical signatures. Andrew Vanderburg, lead researcher at the UW-Madison astronomy department, believes that this is the most exciting aspect of this research- its implications both for exoplanet habitability and our ability to find evidence of these signs of life out in the Universe beyond.