arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2108.08889astro-ph.EP
收藏

四颗亚海王星系外行星的K2、斯皮策和TESS凌日

K2, Spitzer, and TESS Transits of Four Sub-Neptune Exoplanets

Alison Duck, Caleb K. Harada, Justin Harrell, Ryan R. A. Morris, Edward Williams, Ian Crossfield, Michael Werner, Drake Deming

摘要:

我们提出了新的斯皮策过境观测四个K2过境亚海王星:K2- 36 c,K2- 79 b,K2- 167 b和K2- 212 b。我们得出更新的轨道星历和半径为这些行星的斯皮策,TESS和K2测光的联合分析的基础上。我们使用的EVEREST管道,以提供改进的K2测光,通过去趋势仪器噪声和K2的指向抖动。我们使用像素级去相关方法的斯皮策观测,以减少仪器系统的影响。我们模拟了可能的混合食双星的影响,试图通过凌日的消色差性(K2与斯皮策)来验证这些行星。然而,我们发现斯皮策的信噪比这些小行星是不够的,以验证他们通过消色差。然而,通过K2和斯皮策观测之间的联合拟合半径,我们能够独立地确认K2半径测量。由于K2和斯皮策观测之间的基线时间较长,与单独的K2观测相比,我们还能够提高轨道周期的精度。K2- 36 c的改进是3倍,其余行星的改进超过一个数量级。考虑到JWST在1/2023年的可能观测,这些行星过境时间的1 σ不确定性范围从74分钟到434分钟,但我们已经将其减少到8分钟到23分钟。

英文摘要:

We present new Spitzer transit observations of four K2 transiting sub-Neptunes: K2-36c, K2-79b, K2-167b, and K2-212b. We derive updated orbital ephemerides and radii for these planets based on a joint analysis of the Spitzer, TESS, and K2 photometry. We use the EVEREST pipeline to provide improved K2 photometry, by detrending instrumental noise and K2's pointing jitter. We used a pixel level decorrelation method on the Spitzer observations to reduce instrumental systematic effects. We modeled the effect of possible blended eclipsing binaries, seeking to validate these planets via the achromaticity of the transits (K2 versus Spitzer). However, we find that Spitzer's signal-to-noise ratio for these small planets is insufficient to validate them via achromaticity. Nevertheless, by jointly fitting radii between K2 and Spitzer observations, we were able to independently confirm the K2 radius measurements. Due to the long time baseline between the K2 and Spitzer observations, we were also able to increase the precision of the orbital periods compared to K2 observations alone. The improvement is a factor of 3 for K2-36c, and more than an order of magnitude for the remaining planets. Considering possible JWST observations in 1/2023, previous 1 sigma uncertainties in transit times for these planets range from 74 to 434 minutes, but we have reduced them to the range of 8 to 23 minutes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑