2390044

Target RA (J2000): 207.526169 and deg Target Dec (J2000): -40.83580 and deg Gaia GMag: 9.615 Programme ID: CH_PR240017 PI of observing programme: Chakraborty Title of programme: Accurate and precise characterisation of the HIP 67522 system in the presence of significant stellar variability Abstract: Young planets are excellent laboratories to test planet formation and evolution pathways. However the accurate characterisation of parameters like the radius of the planet is limited by the enhanced activity of the host star. The impact of features like unocculted and occulted active regions is a growing challenge in the era of high-precision photometry and transmission spectroscopy and better characterisation of these features is now more vital than ever for the correct interpretation of atmospheres on exoplanets. Here we propose to precisely characterise the HIP 67522 system a 17 Myr Solar-like star exhibiting significant stellar activity and one of the youngest planet-hosting stars discovered to date. The HIP 67522 system consists of one confirmed transiting hot Jupiter (planet b) and an unconfirmed outer planet candidate (planet c). To characterise this key young system we aim to: i) obtain an accurate and precise radius measurement for the known transiting planet (planet b) by quantifying the effect of stellar activity on its transit depth and ii) confirm the candidate exoplanet (planet c) by following up the most likely period aliases of its two known transits. While accurately measuring the radius of planet b is vital for testing different planet formation and evolution models for hot Jupiters confirming planet c will make this the youngest multi-planet transiting system ever discovered making this a very compelling system to be observed by CHEOPS. [truncated! Please see actual data for full text]

目标赤经（J2000）：207.526169 度，目标赤纬（J2000）：-40.83580 度，盖亚G星等（Gaia GMag）：9.615，项目编号（Programme ID）：CH_PR240017，观测项目首席研究员（Principal Investigator，PI）：查克拉博蒂（Chakraborty），项目标题：存在显著恒星活动的HIP 67522系统的高精度表征，摘要：年轻行星是检验行星形成与演化路径的理想实验室。然而，行星半径等参数的精确表征受宿主恒星增强活动的制约。在高精度测光与透射光谱学时代，未掩蔽与已掩蔽活动区等特征的影响正成为日益严峻的挑战，而对这些特征的精准表征，对于正确解读系外行星大气而言，比以往任何时候都更为关键。本研究拟对HIP 67522系统开展精准表征：该系统拥有一颗年龄为17百万年的类太阳恒星，其表现出显著的恒星活动，是迄今发现的最年轻的拥有行星的恒星之一。HIP 67522系统包含一颗已确认的凌星热木星（行星b），以及一颗未确认的系外行星候选体（行星c）。为表征这一关键的年轻行星系统，我们的研究目标为：一、通过量化恒星活动对其凌星深度的影响，实现对已知凌星行星（行星b）的高精度半径测量；二、通过追踪其两次已知凌星事件最可能的周期混叠信号，确认该系外行星候选体（行星c）。精准测量行星b的半径，对于检验热木星的各类行星形成与演化模型至关重要；而确认行星c，则将使该系统成为迄今发现的最年轻的多行星凌星系统，这也让其成为CHEOPS望远镜极具观测价值的目标。[已截断！完整文本请查阅原始数据]