HD 206893 c is on the boundary between a planet and a brown dwarf, or “failed star.”
A group of scientists from around the world, with Professor Sasha Hinkley from the University of Exeter leading the team, have recently discovered a new exoplanet known as HD 206893 c. What makes this discovery particularly significant is that it was the first to be directly imaged using the Gaia spacecraft from Europe. The exoplanet is situated approximately 300 million miles away from the star HD 206893, which is located around 130 light-years from Earth and is approximately 30% bigger than our sun.
The star was regarded as a strong contender for identifying new exoplanets due to its known debris disk around it. The astrometric data that the Gaia mission provides enabled the researchers to measure the wobble of stars, thus inferring the presence of exoplanets. With the aid of the GRAVITY instrument on the Very Large Telescope in northern Chile, the team was able to directly confirm the presence of the newly discovered planet.
Additionally, the observation allowed the team to analyze the light spectrum from the planet’s atmosphere. They found that the object appeared to be brightening, indicating that the core of the giant planet was undergoing nuclear fusion with deuterium, an isotope of hydrogen carrying a neutron. The size of the newly discovered exoplanet is likely to be around 13 times more massive than Jupiter. Such an enormous size, coupled with the evidence of fusion, implies that the exoplanet is on the boundary between being a planet and a brown dwarf. The discovery could give new insights to scientists in distinguishing between massive planets and brown dwarfs.
“The discovery of HD 206893 c is a really important moment for the study of exoplanets, as ours may be the first direct detection of a ‘Gaia exoplanet,'” Hinkley said in a statement(opens in new tab).
The findings from this discovery demonstrate that Gaia can be used to pinpoint the location of potential exoplanets, which can then be directly detected by follow-up observations either on the ground or through a space-based observatory such as NASA’s James Webb Space Telescope.
The study has been accepted by the journal Astronomy & Astrophysics and is available through ArXiv. Moreover, Professor Hinkley presented the team’s discovery at the American Astronomical Society conference in Seattle earlier this month.