Astronomers using the James Webb Space Telescope have captured evidence of a planet with a mass similar to Saturn orbiting the young nearby star TWA 7. The discovery, made by an international team led by Dr. Anne-Marie Lagrange, would represent Webb’s first direct image detection of a planet and the lightest planet ever seen using this technique.
Using Webb’s Mid-Infrared Instrument (MIRI) and its coronagraph, the team detected a faint infrared source near TWA 7, which matches the expected position of a planet. The source is located about 50 times closer to the star than Earth is to the Sun, in a gap within one of three dust rings discovered around TWA 7.
The object, referred to as TWA 7b, could be a young, cold planet with a mass around 0.3 times that of Jupiter and a temperature near 320 Kelvin (47 degrees Celsius). Its location aligns with the ring’s dynamics, hinting at an interaction between the planet and its surroundings.
This discovery would mark the first time a planet has been directly associated with sculpting a debris disc and could offer an observational hint of a Trojan disc – a collection of dust trapped in the planet’s orbit. TWA 7 is a young (~6.4 million years old) M-type star located about 111 light-years away, making it an ideal target for Webb’s mid-infrared observations.
The findings highlight Webb’s ability to explore previously unseen low-mass planets around nearby stars. Ongoing and future observations will aim to better constrain the properties of the candidate, verify its planetary status, and deepen our understanding of planet formation and disc evolution in young systems.
Source: https://www.esa.int/Science_Exploration/Space_Science/Webb/Webb_finds_evidence_of_a_lightweight_planet_around_TWA_7