The first evidence of a gas giant planet orbiting a white dwarf star has been found by scientists using the ESO Very Large Telescope (VLT). The gas giant orbits the hot white dwarf star, which is said to be the remnants of a star that was once much like our Sun. The scientists say that this solar system hints at what our own may look like in the distant future.
The team says that the gas giant is orbiting the star at close range and that the close orbit is causing the atmosphere of the planet to be stripped away to form a disc of gas around the star. The discovery of the solar system was by chance, according to researcher Boris Gänsicke. The team was inspecting about 7,000 white dwarf stars that were observed by the Sloan Digital Sky Survey and found one that was unlike all the others.
The team speculated initially that the difference in that solar system and the others around white dwarfs might be due to a planetary remnant in orbit. The white dwarf star in question is called WDJ0914+1914. Using the X-shooter instrument on the ESO VLT, the team make follow-up observations that confirmed the presence of hydrogen, oxygen, and sulfur in a disc of gas swirling into the white dwarf, rather than coming from the star.
The team says that it took a few weeks to figure out that the only way to make a disc of that type was by the evaporation of a giant planet. The team said that the detected amounts of hydrogen, oxygen, and sulfur are similar to those found in deep atmospheric layers of icy, giant planets like Neptune and Uranus. The team says that if planets such as those were orbiting close to a hot white dwarf star, the extreme ultraviolet radiation for the star would strip away its outer layers, and some of that gas would turn into a disc accreting onto the white dwarf star.