The European Space Agency’s (ESA) Gaia mission has made a groundbreaking discovery, confirming the existence of a massive exoplanet and a brown dwarf in the Milky Way galaxy. By measuring the positions and velocities of over 1 billion stars, Gaia created a 3D map of the galaxy that will provide valuable insights for years to come.
Gaia was initially designed to study astrometry, but it inadvertently detected several planets during its observations. To confirm these detections, researchers used the NEID spectrograph at the NSF’s Kitt Peak National Observatory to measure the stellar wobbles caused by the planets’ gravitational pull. The results have been published in a paper titled “Gaia-4b and 5b: Radial Velocity Confirmation of Gaia Astrometric Orbital Solutions Reveal a Massive Planet and a Brown Dwarf Orbiting Low-mass Stars.”
The confirmed exoplanet, named Gaia-4b, has a mass of approximately 11.8 Jupiter masses and orbits a star with a mass of 0.644 solar masses every 571 days. This massive planet is an outlier in exoplanet discoveries, as it was formed around a low-mass star, which is unusual.
Another discovery is the brown dwarf Gaia-5b, which has a mass of about 21 Jupiter masses and orbits its star every 358 days. The study highlights the effectiveness of combining different observational techniques, such as astrometry and radial velocity spectroscopy, to detect exoplanets and brown dwarfs.
The confirmation of these massive planets and brown dwarfs provides valuable insights into planet formation theories and solar system architecture. Astronomers expect to find more of these massive objects in Gaia data and confirm them using spectrographs like NEID. The study’s findings represent the tip of the iceberg, enabling key insights into the masses and orbital architectures of numerous massive planets at intermediate orbital periods.
Source: https://www.universetoday.com/170755/gaia-was-right-it-did-find-a-planet