In News:

Astronomers using NASA's James Webb Space Telescope (JWST) discovered a hidden giant exoplanet, Beta Pictoris d, in the Beta Pictoris star system, located about 63 light-years from Earth.

About the Beta Pictoris System

• The Beta Pictoris system is a young planetary system, estimated to be around 23 million years old, making it an important laboratory for studying planet formation and the evolution of planetary systems.
• Located in the Milky Way Galaxy, the system is surrounded by a bright dust and debris disk, which provides valuable insights into interactions between planets and surrounding material.
• Before this discovery, the system was known to contain two directly imaged giant exoplanets—Beta Pictoris b and Beta Pictoris c. With the discovery of Beta Pictoris d, it has become the second known planetary system with at least three directly imaged exoplanets.

About Beta Pictoris d

• Beta Pictoris d is a gas giant exoplanet with an estimated mass of at least twice that of Jupiter, making it the smallest among the three known giant planets in the system.
• It orbits its host star at a distance of about 30 Astronomical Units (AU), roughly comparable to Neptune's orbit around the Sun, and has the widest orbit among the three planets.
• The planet remained undetected for years because it lies within one of the brightest known debris disks, making conventional imaging extremely difficult.

Discovery Method

• The planet was discovered using the Near-Infrared Spectrograph (NIRSpec) Integral Field Unit aboard the James Webb Space Telescope while scientists were observing Beta Pictoris b.
• Instead of direct imaging alone, researchers identified the planet through its spectroscopic chemical signature. Detection of carbon monoxide absorption lines and radial velocity analysis confirmed its planetary nature.
• Subsequent observations using JWST's Mid-Infrared Instrument (MIRI) detected water vapour and methane in its atmosphere, providing further confirmation.