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arXiv 1802.09557astro-ph.EP
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1:3:5近共振行星凌日GJ 9827(K2-135)的质量测定

Mass determination of the 1:3:5 near-resonant planets transiting GJ 9827 (K2-135)

J. Prieto-Arranz, E. Palle, D. Gandolfi, O. Barragán, E. W. Guenther, F. Dai, M. Fridlund, T. Hirano, J. Livingston, P. Niraula, C. M. Persson, S. Redfield, S. … 展开作者

J. Prieto-Arranz, E. Palle, D. Gandolfi, O. Barragán, E. W. Guenther, F. Dai, M. Fridlund, T. Hirano, J. Livingston, P. Niraula, C. M. Persson, S. Redfield, S. Albrecht, R. Alonso, G. Antoniciello, J. Cabrera, W. D. Cochran, Sz. Csizmadia, H. Deeg, Ph. Eigmüller, M. Endl, A. Erikson, M. E. Everett, A. Fukui, S. Grziwa, A. P. Hatzes, D. Hidalgo, M. Hjorth, J. Korth, D. Lorenzo-Oliveira, F. Murgas, N. Narita, D. Nespral, G. Nowak, M. Pätzold, P. Montañés Rodríguez, H. Rauer, I. Ribas, A. M. S. Smith, V. Van Eylen, J. N. Winn

摘要:

目的。GJ 9827(K2-135)最近被发现拥有一个紧密堆积的系统,由三颗过境的小行星组成,它们的轨道周期分别为1.2、3.6和6.2天,接近1:3:5的比例。GJ 9827是开普勒和K2探测到的最近的行星系统(d = $30.32\pm1.62$ pc)。它的亮度(V = 10.35等)使它成为详细研究其行星性质的理想目标。结果我们发现GJ 9827 b的质量为$M_\mathrm{b}=3.74^{+0.50}_{-0.48}$ $M_\oplus$,半径为$R_\mathrm{b}=1.62^{+0.17}_{-0.16}$ $R_\oplus$,平均密度为$ρ_\mathrm{b} = 4.81^{+1.97}_{-1.33}$ g cm $^{-3}$。GJ 9827 c的质量为$M_\mathrm{c}=1.47^{+0.59}_{-0.58}$ $M_\oplus$,半径为$R_\mathrm{c}=1.27^{+0.13}_{-0.13}$ $R_\oplus$,平均密度为$ρ_\mathrm{c}= 3.87^{+2.38}_{-1.71}$ g cm $^{-3}$。对于GJ 9827 d,我们推导出$M_\mathrm{d}=2.38^{+0.71}_{-0.69}$ $M_\oplus$、$R_\mathrm{d}=2.09^{+0.22}_{-0.21}$ $R_\oplus$和$ρ_\mathrm{d}= 1.42^{+0.75}_{-0.52}$ g cm $^{-3}$。结论. GJ 9827是少数已知的凌日行星系统之一,其所有行星的质量都被确定,精度优于30%。这个系统特别有趣,因为这三颗行星都接近超级地球和迷你海王星之间的极限。我们还发现,行星的整体组成是兼容的情况下,所有三颗行星形成类似的核心/大气成分,我们推测,虽然GJ 9827 b和GJ 9827 c失去了它们的大气层信封,GJ 9827 d保持其大气层,由于低得多的恒星辐射。这使得GJ 9827成为少数几个可以详细研究所有行星的动力学演化和大气逃逸的系统之一,帮助我们了解紧凑系统的形成和演化。

英文摘要:

Aims. GJ 9827 (K2-135) has recently been found to host a tightly packed system consisting of three transiting small planets whose orbital periods of 1.2, 3.6, and 6.2 days are near the 1:3:5 ratio. GJ 9827 hosts the nearest planetary system (d = $30.32\pm1.62$ pc) detected by Kepler and K2 . Its brightness (V = 10.35 mag) makes the star an ideal target for detailed studies of the properties of its planets. Results. We find that GJ 9827 b has a mass of $M_\mathrm{b}=3.74^{+0.50}_{-0.48}$ $M_\oplus$ and a radius of $R_\mathrm{b}=1.62^{+0.17}_{-0.16}$ $R_\oplus$, yielding a mean density of $ρ_\mathrm{b} = 4.81^{+1.97}_{-1.33}$ g cm$^{-3}$. GJ 9827 c has a mass of $M_\mathrm{c}=1.47^{+0.59}_{-0.58}$ $M_\oplus$, radius of $R_\mathrm{c}=1.27^{+0.13}_{-0.13}$ $R_\oplus$, and a mean density of $ρ_\mathrm{c}= 3.87^{+2.38}_{-1.71}$ g cm$^{-3}$. For GJ 9827 d we derive $M_\mathrm{d}=2.38^{+0.71}_{-0.69}$ $M_\oplus$, $R_\mathrm{d}=2.09^{+0.22}_{-0.21}$ $R_\oplus$, and $ρ_\mathrm{d}= 1.42^{+0.75}_{-0.52}$ g cm$^{-3}$. Conclusions. GJ 9827 is one of the few known transiting planetary systems for which the masses of all planets have been determined with a precision better than 30%. This system is particularly interesting because all three planets are close to the limit between super-Earths and mini-Neptunes. We also find that the planetary bulk compositions are compatible with a scenario where all three planets formed with similar core/atmosphere compositions, and we speculate that while GJ 9827 b and GJ 9827 c lost their atmospheric envelopes, GJ 9827 d maintained its atmosphere, owing to the much lower stellar irradiation. This makes GJ 9827 one of the very few systems where the dynamical evolution and the atmospheric escape can be studied in detail for all planets, helping us to understand how compact systems form and evolve.

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。

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