| Name: | Bihan Banerjee |
| Affiliation: | Tata Institute of Fundamental Research, Mumbai |
| Conference ID : | ASI2024_591 |
| Title : | Understanding the formation and evolution of close-in planets |
| Authors : | Bihan Banerjee1, Manoj Puravankara1, Mayank Narang2, Himanshu Tyagi1, Arun Surya3, Ayanabha De1, Prashanta Kumar Nayak4, Mihir Tripathi2, Vinod C Pathak1 |
| Authors Affiliation: | 1Tata Institute of Fundamental research Mumbai
2Academia Sinica Institute of Astronomy and Astrophysics, Taiwan
3Indian Institue of Astrophysics, Bangalore
4Institute of Astrophysics, Pontificia, Universidad Catolica de Chile |
| Mode of Presentation: | Oral |
| Abstract Category : | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract : | A significant number of detected planets orbit their host stars in close proximity, a configuration starkly different from our solar system. The formation and evolution of these close-in planets are not well understood, prompting this study to investigate potential insights from close-in planets and host star data.
1. The evolution of close-in planets is largely shaped by atmospheric photoevaporation, driven by high energy radiation from host stars. Notably, a gap exists in the radius-period diagram between super Earths and mini Neptunes, primarily shaped by photoevaporation. To explore this phenomenon, a forward model focused on photoevaporation has been developed, successfully reproducing the gap and matching established mass-radius trends for small planets. This model provides valuable constraints on initial distributions and predicts patterns such as the temporal evolution of the "evaporation valley" and the mass-radius relationship. The ionization structure of a planet's atmosphere plays a crucial role in determining the nature of photoevaporation. Using 1d hydrodynamic code ATES, computing the average recombination to advection rate ratio in the atmosphere, we have divided photoevaporating planets into three distinct regimes.
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2. Host stars of Jupiter-like planets tend to be, on average, both more metal-rich and younger compared to stars hosting smaller planets, reflecting the metallicity-age connection. However, an analysis of metallicities and ages from Gaia DR3 data for host stars of hot, warm, and cold Jupiters with varying eccentricities revealed intriguing findings. Host stars of hot Jupiters and cold eccentric Jupiters display higher metallicity, supporting a common origin likely linked to high eccentricity tidal migration. Nevertheless, a distinction emerges in the age of these host stars, with hot Jupiter hosts appearing relatively younger, hinting at the possibility that older hot Jupiters may be undergoing tidal engulfment by their parent stars, thus providing insights into the average stellar tidal factor.
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