[论文解读] Observational Signatures of Planetary Tidal Disruption Events Around Solar-Mass Stars

Matías Montesinos, Sergei Nayakshin+5 more|arXiv (Cornell University)|Jan 18, 2026

Astro and Planetary Science被引用 1

一句话总结

本论文在太阳质量恒星周围进行2D水动力模拟的行星潮汐破坏事件（TDE），预测木星样与海王星样前体在多波段的光曲线与颜色随时间的演化，并考察不同轨道偏心率的影响。结果显示前体质量与偏心率如何在多年尺度上塑形碎片演化与可观测特征。

ABSTRACT

The tidal disruption of planets by their host stars represents a growing area of interest in transient astronomy, offering insights into the final stages of planetary system evolution. We model the hydrodynamic evolution and predict the multi-wavelength observational signatures of planetary TDEs around a solar-mass host, focusing on Jupiter-like and Neptune-like progenitors and examining how different eccentricities of the planet's pre-disruption orbit shape the morphology and emission of the tidal debris. We perform 2D hydrodynamic simulations using the FARGO3D code to model the formation and viscous evolution of the resulting debris disk. We employ a viscous alpha-disk prescription and include a time-dependent energy equation to compute the disk's effective temperature and subsequently derive the bolometric and multi-band photometric light curves. Our simulations show that planetary TDEs produce a diverse range of luminous transients. A Jupiter-like planet disrupted from a circular orbit at the Roche limit generates a transient peaking at $L_{bol} \approx 10^{38}$ erg s$^{-1}$ after a 12-day rise. In contrast, the same planet on an eccentric orbit (e=0.5) produces a transient of comparable peak luminosity but on a much shorter timescale, peaking in only 1 day and followed by a highly volatile light curve. We find that the effect of eccentricity is not universal, as it accelerates the event for Jupiter but delays it for Neptune. A robust "bluer-when-brighter" colour evolution is a common feature as the disk cools over its multi-year lifetime. The strong dependence of light curve morphology on the initial orbit and progenitor mass makes these events powerful diagnostics. This framework is crucial for identifying planetary TDEs in time-domain surveys.

研究动机与目标

• 模型化太阳质量恒星引力作用下行星碎片的水动力学演化。
• 预测总光度与多波段光曲线及颜色随时间的演化。
• 研究前体质量与轨道偏心率如何影响光曲线形态与观测量。
• 提供理论模板，帮助在时域 surveys 中识别行星TDEs。

提出的方法

• 使用FARGO3D代码进行2D水动力学模拟。
• 粘性α-盘设定（alpha=1e-3）并加入时间依赖能量方程。
• 通过有效光学深度τ_eff及Hubeny不透明度形式实现显式辐射冷却。
• 热力学闭合采用理想气体方程和固定平均分子量μ=2.35。
• 利用局部T_eff与Planck函数生成多波段光曲线；分析颜色指数。
• 后处理放射传输，使用RADMC-3D生成合成图像。

实验结果

研究问题

• RQ1 初始轨道（e=0 与 e=0.5）如何影响碎片圆化和随后的粘性演化？
• RQ2 在太阳质量恒星的 Roche 极限处被破坏的木星样与海王星样行星的光度曲线（总光度）预测为何？
• RQ3 轨道偏心率与前体质量如何影响行星TDEs的峰值 luminosity、时间尺度和颜色演化（蓝色越亮越显）？
• RQ4 哪些观测信号（光曲线、光谱、图像）可在时域 surveys 中将行星TDEs与直接星-行星合并区分开？

主要发现

• 圆轨道的木星样行星的总光度峰值约为 L_peak ≈ 1.69×10^38 erg s^-1，峰值时间约 t_peak ≈ 12.4 天。
• 轨道偏心率为 e=0.5 的木星样行星产生了可比的峰值光度，但上升时间显著更短（约1 天），光曲线波动较大。
• 在基准情形（e=0）中，海王星样破坏事件较木星样更暗但持续时间更长。
• 偏心率使木星的光曲线加速，而对海王星则延迟并拉长，显示质量与轨道的二象性依赖。
• 预测在多年的寿命中，会出现稳健的蓝色越亮越显（blue-when-brighter）颜色演化。