| Name: | Akanksha Khandelwal |
| Affiliation: | Physical Research Laboratory, Ahmedabad |
| Conference ID : | ASI2023_557 |
| Title : | Discovery of a massive giant planet in an eccentric orbit around a sub-giant star |
| Authors : | Akanksha Khandelwal, and Rishikesh Sharma, Abhijit Chakraborty, Priyanka Chaturvedi, Solène Ulmer-Moll, David R. Ciardi, Andrew W. Boyle, Sanjay Baliwal, Eike. W. Guenther, Neelam J.S.S.V. Prasad, Ashirbad Nayak, Monika Lendl, Christoph Mordasini |
| Mode of Presentation: | Oral |
| Abstract Category : | Stars, ISM and Galaxy |
| Abstract : | Massive giant planets (4 to 13 Mj) have always been debated whether these objects should be classified as planets or Brown dwarfs, and their presence in close-in orbit has always puzzled astronomers. Recently, we have discovered a transiting massive giant planet around TOI-4603, a sub-giant F-type star from NASA's Transiting Exoplanet Survey Satellite (TESS). In this meeting, I will talk about the results related to the discovery and characterization of this newly detected exoplanet. The planet has a radius of 1.043 Rj and an orbital period of 7.24600 days. Using radial velocity measurements with the PARAS (PRL) spectrograph, we determined the planet's mass to be 12.69 Mj, resulting in a bulk density of 13.9 g /cm^3. This makes it one of the few massive giant planets with extreme density and lies in the transition mass region of massive giant planets and low-mass brown dwarfs, an important addition to the population of fewer than five objects in this mass range. Additionally, the planet is also going through high eccentricity tidal migration, which will help in understanding the planet migration theories. The planet is modeled with no central core, and all the heavy elements (assumed water) are mixed in the gaseous envelope. We find a heavy elements fraction of 0.14 and metal enrichment of the planet (Zp/Zstar) of 4.8. It does not follow the traditional planet occurrence-metallicity trend for massive giant planets, which makes it an interesting target for further detailed study of planet formation and its interior. The detection of such systems will provide us with valuable insights into the governing processes of massive planets, as well as enhance our understanding of their dominant formation and migration mechanisms. |
