Elias 2-24 is a heavily accreting T Tauri star surrounded by a protoplanetary disk and has one confirmed protoplanet inside the disk gap. At the time of confirmation, the planet is the youngest exoplanet discovered, with an age younger than 1 Myr.
The system is named after J. H. Elias and is part of a catalog of infrared sources in the Rho Ophiuchi Cloud complex.
Protoplanetary disk The disk around the star has a mass of around 0.12 . The disk gaps were first noticed in 2017 using ALMA continuum observations. The middle gap is located at 52 astronomical units (AU) and has a width of 28 AU. The researchers estimated that this gap hosts a planet with a mass of 1 to 8 . Another study with ALMA found that the gap is produced by a protoplanet with a mass of around 0.7 . A higher resolution ALMA image was obtained with DSHARP. The observation showed one gap at 57 AU, consistent with the middle gap of the previous observation. It also showed a narrow ring at 77 AU, which is consistent with the simulation of a disk with a 0.8 protoplanet inside it. ALMA observations showed that the CO gas disk kinematics are disturbed by the protoplanet. Additionally the image showed traces of a spiral wake produced by the orbiting protoplanet.
Protoplanet A candidate protoplanet was first detected in 2021 using the Very Large Telescope NaCo instrument in the infrared L' band at 55 au inside the gap of the protoplanetary disk. Later a carbon monoxide (CO) emission was detected with ALMA at the position of the candidate. The morphology of the bright spot is consistent with emission by a circumplanetary disk. The protoplanet was recovered with Keck NIRC2 observations. This study also confirmed the planetary nature of this source. The mass was estimated between 1.9 and 4.0 . The researchers caution that this estimate is an upper limit because of strong disk extinction and accretion effects. The protoplanet has a temperature between to , meaning it could be similar to L dwarfs or T dwarfs. Because of the young age of less than 1 Myr, the planet is at an early stage of its formation. At this stage the planet is rapidly gaining mass by accreting its envelope.
Gallery
References