The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau
The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau
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DOI：
10.1093/mnras/stw2904
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发表时间：
2016-11
影响因子：
4.8
通讯作者：
J. Donati;J. Donati;Louise Yu;Louise Yu;C. Moutou;A. C. Cameron;L. Malo;K. Grankin;E. H'ebrard;G. Hussain;A. Vidotto;S. Alencar;R. Haywood;J. Bouvier;Pascal Petit;Pascal Petit;M. Takami;G. Herczeg;S. G. Gregory;M. Jardine;J. Morin
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作者：
J. Donati;J. Donati;Louise Yu;Louise Yu;C. Moutou;A. C. Cameron;L. Malo;K. Grankin;E. H'ebrard;G. Hussain;A. Vidotto;S. Alencar;R. Haywood;J. Bouvier;Pascal Petit;Pascal Petit;M. Takami;G. Herczeg;S. G. Gregory;M. Jardine;J. Morin
我们报告的结果扩展的光谱偏振和光度监测的弱线金牛座T星星V830头和它最近发现的新生的近距离巨行星。我们的观测是在MaTYSSE计划内进行的，时间跨度超过91天，涉及ESPaDOns和Narval分光偏振仪，这些分光偏振仪与3.6米的加拿大-法国-夏威夷望远镜、2米的Bernard Lyot望远镜和8米的双子座-北望远镜相连。使用塞曼多普勒成像，我们表征的表面亮度分布，磁拓扑结构和表面差异旋转的V830头在我们的观测时间，并证明这两个分布随时间的演变超出了预期的差异旋转。我们还报告说，在我们的观测接近尾声时，V830 Tau触发了一个主要的耀斑和两个较弱的前体，在多个光谱活动代理中表现为增强的红移发射。采用3种不同的滤波技术，模拟了V830 Tau产生的径向速度（RV）活动抖动（半幅值为1.2km/s），成功地提取了隐藏在抖动背后的68 m/s RV行星信号，进一步证实了V830 Tau B的存在，并更好地表征了其轨道参数。我们发现，基于高斯过程回归的方法表现最好，这要归功于其更高的建模能力，不仅是活动抖动，而且在我们的观察过程中，它的时间演变，并成功地再现我们的RV数据的均方根精度为35米/秒。我们的研究结果提供了新的观测限制的情况下，星星/行星的形成，并展示了大规模的搜索附近的巨行星围绕金牛座T恒星的科学潜力。
We report results of an extended spectropolarimetric and photometric monitoring of the weak-line T Tauri star V830 Tau and its recently-detected newborn close-in giant planet. Our observations, carried out within the MaTYSSE programme, were spread over 91d, and involved the ESPaDOnS and Narval spectropolarimeters linked to the 3.6m Canada-France-Hawaii, the 2m Bernard Lyot and the 8-m Gemini-North Telescopes. Using Zeeman-Doppler Imaging, we characterize the surface brightness distributions, magnetic topologies and surface differential rotation of V830 Tau at the time of our observations, and demonstrate that both distributions evolve with time beyond what is expected from differential rotation. We also report that near the end of our observations, V830 Tau triggered one major flare and two weaker precursors, showing up as enhanced red-shifted emission in multiple spectral activity proxies. With 3 different filtering techniques, we model the radial velocity (RV) activity jitter (of semi-amplitude 1.2km/s) that V830 Tau generates, successfully retrieve the 68m/s RV planet signal hiding behind the jitter, further confirm the existence of V830 Tau b and better characterize its orbital parameters. We find that the method based on Gaussian-process regression performs best thanks to its higher ability at modelling not only the activity jitter, but also its temporal evolution over the course of our observations, and succeeds at reproducing our RV data down to a rms precision of 35m/s. Our result provides new observational constraints on scenarios of star / planet formation and demonstrates the scientific potential of large-scale searches for close-in giant planets around T Tauri stars.