| Name: | SHRADDHA BISWAS |
| Affiliation: | INDIAN CENTRE FOR SPACE PHYSICS |
| Conference ID: | ASI2025_55 |
| Title: | Investigating the Potential Causes of Transit Timing Variations for TrES-2b in the Era of TESS. |
| Authors: | Shraddha Biswas1, D. Bisht1, Ing-Guey Jiang2, Devesh P. Sariya2, and Kaviya Parthasarathy2 |
| Authors Affiliation: | 1 Indian Centre for Space Physics, 466 Barakhola, Singabari Road, Netai Nagar, Kolkata, West Bengal 700099, India
2 Department of Physics and Institute of Astronomy, National Tsing-Hua University, Hsinchu 30013, Taiwan |
| Mode of Presentation: | Oral |
| Abstract Category: | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract: | Transit timing variations (TTVs) have emerged as a crucial methodology in the field of exoplanetary science, allowing researchers to detect and characterize exoplanets by examining fluctuations in their transit times. In our investigation of the TTVs associated with the hot Jupiter TrES-2b, we compiled data from 64 high-quality transit light curves obtained from all seven sectors of NASA's Transiting Exoplanet Survey Satellite (TESS). This dataset was further enhanced with 60 optimal light curves sourced from the Exoplanet Transit Database and integrated with 106 mid-transit times from previous research.
Our comprehensive analysis of these transit timings indicated a significant improvement in the orbital ephemerides of TrES-2b; however, we did not detect any short-period TTVs that would suggest the presence of an additional body in the system. The lack of observable short-term TTVs encourages a deeper investigation into long-term TTVs, which could be influenced by phenomena such as orbital decay, apsidal precession, the Applegate mechanism, and the Rømer effect. Among these potential causes, orbital decay emerged as the most plausible explanation for the observed TTVs, supported by a ΔBIC value of 4.32.
We estimate that the orbital period of TrES-2b is decreasing at a rate of approximately –5.58 ± 1.81 ms yr⁻¹. Assuming that this decay is primarily a result of tidal dissipation within the host star, we calculated the stellar tidal quality factor to be approximately 9.9 × 10³. This value is 2–3 orders of magnitude lower than theoretical predictions for other hot Jupiter systems, suggesting a more efficient tidal dissipation mechanism at play within the host star. To further elucidate the underlying causes of the observed changes in the orbital period, additional precise photometric and radial velocity measurements will be necessary.
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