论文标题
TNG XXVII的差距程序。与Harps-N一起重新评估年轻的行星系统:热木星V830 Tau B真的在那里吗?
The GAPS Programme at TNG XXVII. Reassessment of a young planetary system with HARPS-N: is the hot Jupiter V830 Tau b really there?
论文作者
论文摘要
在非常年轻的恒星周围($ <$ 10的MYR)周围检测和表征外生世界是系外行星人口研究的关键方面,尤其是用于了解行星形成和迁移的机制和时间表。但是,仅使用径向速度法的检测可能非常具有挑战性,因为由于这种恒星的磁性活性而引起的信号的幅度可能比即使是由大行星引起的数量级都大的数量级。我们观察了非常年轻的($ \ sim $ 2 Myr)和非常活跃的Star v830 Tau与Harps-n光谱仪独立确认并表征了先前报道的先前报道的热木星V830 tau b($ k _ {\ rm b} = 68 \ pm11 $ m/s; $ m_ {jup} $; $ p _ {\ rm b} = 4.927 \ pm0.008 $ d)。由于观察到的$ \ sim $ 1 km/s的径向速度散射显然可归因于V830 tau的磁性活动,因此我们分析了用不同管道提取的径向速度,并使用几种最先进的工具对其进行了建模。我们设计了注射恢复模拟,以支持我们的结果并表征我们的检测极限。通过同时使用光度和光谱诊断来帮助径向速度的分析。尽管我们的HARP-N数据质量高以及我们执行的测试的多样性,但我们无法在数据中检测到Planet V830 Tau B并确认其存在。我们的模拟表明,对声称的行星多普勒信号的统计意义检测非常具有挑战性。尽管重要的是要继续搜索年轻恒星周围的行星,这一点很重要,因此必须格外小心,以克服要面对的技术困难以实现其检测和表征。当评估其发生率,形成机制和迁移途径时,必须牢记这一点,尤其是没有光度传输中存在的证据。
Detecting and characterising exoworlds around very young stars (age$<$10 Myr) are key aspects of exoplanet demographic studies, especially for understanding the mechanisms and timescales of planet formation and migration. However, detection using the radial velocity method alone can be very challenging, since the amplitude of the signals due to magnetic activity of such stars can be orders of magnitude larger than those induced even by massive planets. We observed the very young ($\sim$2 Myr) and very active star V830 Tau with the HARPS-N spectrograph to independently confirm and characterise the previously reported hot Jupiter V830 Tau b ($K_{\rm b}=68\pm11$ m/s; $m_{\rm b}sini_{\rm b}=0.57\pm0.10$ $M_{jup}$; $P_{\rm b}=4.927\pm0.008$ d). Due to the observed $\sim$1 km/s radial velocity scatter clearly attributable to V830 Tau's magnetic activity, we analysed radial velocities extracted with different pipelines and modelled them using several state-of-the-art tools. We devised injection-recovery simulations to support our results and characterise our detection limits. The analysis of the radial velocities was aided by using simultaneous photometric and spectroscopic diagnostics. Despite the high quality of our HARPS-N data and the diversity of tests we performed, we could not detect the planet V830 Tau b in our data and confirm its existence. Our simulations show that a statistically-significant detection of the claimed planetary Doppler signal is very challenging. Much as it is important to continue Doppler searches for planets around young stars, utmost care must be taken in the attempt to overcome the technical difficulties to be faced in order to achieve their detection and characterisation. This point must be kept in mind when assessing their occurrence rate, formation mechanisms and migration pathways, especially without evidence of their existence from photometric transits.