与浓缩咖啡一起重新访问Proxima

论文标题

与浓缩咖啡一起重新访问Proxima

Revisiting Proxima with ESPRESSO

论文作者

Mascareño, A. Suárez, Faria, J. P., Figueira, P., Lovis, C., Damasso, M., Hernández, J. I. González, Rebolo, R., Cristiano, S., Pepe, F., Santos, N. C., Osorio, M. R. Zapatero, Adibekyan, V., Hojjatpanah, S., Sozzetti, A., Murgas, F., Abreo, M., Affolter, M., Alibert, Y., Aliverti, M., Allart, R., Prieto, C. Allende, Alves, D., Amate, M., Avila, G., Baldini, V., Bandi, T., Barros, S. C. C., Bianco, A., Benz, W., Bouchy, F., Broeng, C., Cabral, A., Calderone, G., Cirami, R., Coelho, J., Conconi, P., Coretti, I., Cumani, C., Cupani, G., D'Odorico, V., Deiries, S., Delabre, B., Di Marcantonio, P., Dumusque, X., Ehrenreich, D., Fragoso, A., Genolet, L., Genoni, M., Santos, R. Génova, Hughes, I., Iwert, O., Ferber, K., Knusdrtrup, J., Landoni, M., Lavie, B., Lillo-Box, J., Lizon, J., Curto, G. Lo, Maire, C., Manescau, A., Martins, C. J. A. P., Mégevand, D., Mehner, A., Micela, G., Modigliani, A., Molaro, P., Monteiro, M. A., Monteiro, M. J. P. F. G., Moschetti, M., Mueller, E., Nunes, N. J., Oggioni, L., Oliveira, A., Pallé, E., Pariani, G., Pasquini, L., Poretti, E., Rasilla, J. L., Redaelli, E., Riva, M., Tschudi, S. Santana, Santin, P., Santos, P., Segovia, A., Sosnoswska, D., Sousa, S., Spanò, P., Tenegi, F., Udry, S., Zanutta, A., Zerbi, F.

论文摘要

我们的目的是使用新的意式浓缩仪仪获得的独立测量值确认近距离B的存在，并利用其提高的精度来完善行星参数。我们分析了2019年期间对接头的63个光谱浓缩症观察结果。我们获得了径向速度测量值，典型的径向速度光子噪声为26 cm/s。我们对径向速度的时间序列和互相关函数的全宽度最高宽度进行了联合MCMC分析，以模拟数据中存在的行星和恒星信号，并应用高斯过程回归以处理出色的活动。我们在浓缩咖啡数据中独立确认了proxima b的存在。浓缩咖啡数据本身显示Proxima b在11.218 $ \ pm $ 0.029天，最低质量为1.29 $ \ pm $ 0.13 ME。在合并的数据集中，我们测量的时间为11.18427 $ \ pm $ 0.00070天，最低质量为1.173 $ \ pm $ 0.086 ME。我们没有发现恒星活动是11.2天信号的潜在原因。我们发现一些证据表明存在第二个短周期信号，在5.15天，半振幅仅为40 cm/s。如果是由行星伴侣引起的，则对应于0.29 $ \ pm $ 0.08 me的最低质量。我们发现，CCF的FWHM可以用作亮度变化的代理，并且其随时间的梯度可用于成功地从恒星活性影响的一部分中成功地降低径向速度数据。浓缩咖啡数据中活性引起的径向速度信号显示了幅度趋向于红色波长。使用光谱仪的红端测量的速度受活动的影响较小，这表明恒星活动是斑点主导的。收集的数据排除了额外的伴侣在短时间内质量高于0.6 Me的额外伴侣的存在。

We aim to confirm the presence of Proxima b using independent measurements obtained with the new ESPRESSO spectrograph, and refine the planetary parameters taking advantage of its improved precision. We analysed 63 spectroscopic ESPRESSO observations of Proxima taken during 2019. We obtained radial velocity measurements with a typical radial velocity photon noise of 26 cm/s. We ran a joint MCMC analysis on the time series of the radial velocity and full-width half maximum of the cross-correlation function to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with stellar activity. We confirm the presence of Proxima b independently in the ESPRESSO data. The ESPRESSO data on its own shows Proxima b at a period of 11.218 $\pm$ 0.029 days, with a minimum mass of 1.29 $\pm$ 0.13 Me. In the combined dataset we measure a period of 11.18427 $\pm$ 0.00070 days with a minimum mass of 1.173 $\pm$ 0.086 Me. We find no evidence of stellar activity as a potential cause for the 11.2 days signal. We find some evidence for the presence of a second short-period signal, at 5.15 days with a semi-amplitude of merely 40 cm/s. If caused by a planetary companion, it would correspond to a minimum mass of 0.29 $\pm$ 0.08 Me. We find that the FWHM of the CCF can be used as a proxy for the brightness changes and that its gradient with time can be used to successfully detrend the radial velocity data from part of the influence of stellar activity. The activity-induced radial velocity signal in the ESPRESSO data shows a trend in amplitude towards redder wavelengths. Velocities measured using the red end of the spectrograph are less affected by activity, suggesting that the stellar activity is spot-dominated. The data collected excludes the presence of extra companions with masses above 0.6 Me at periods shorter than 50 days.

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