Revisiting the transits of CoRoT-7b at a lower activity level
Revisiting the transits of CoRoT-7b at a lower activity level
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DOI：
10.1051/0004-6361/201423939
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发表时间：
2014-07
影响因子：
6.5
通讯作者：
S. Barros;J. Almenara;M. Deleuil;R. Díaz;S. Csizmadia;J. Cabrera;S. Chaintreuil;A. Cameron;A. Hatzes;R. Haywood;Antonino Francesco Lanza;S. Aigrain;R. Alonso;R. Bord'e;F. Bouchy;H. Deeg;A. Erikson;M. Fridlund;S. Grziwa;D. Gandolfi;T. Guillot;E. Guenther;A. Léger;C. Moutou;M. Ollivier;T. Pasternacki;M. Patzold;H. Rauer;D. Rouan;A. Santerne;J. Schneider;G. W. A. M. Universit'e;Cnrs;Lam;Marseille;France.
中科院分区：
文献类型：
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作者：
S. Barros;J. Almenara;M. Deleuil;R. Díaz;S. Csizmadia;J. Cabrera;S. Chaintreuil;A. Cameron;A. Hatzes;R. Haywood;Antonino Francesco Lanza;S. Aigrain;R. Alonso;R. Bord'e;F. Bouchy;H. Deeg;A. Erikson;M. Fridlund;S. Grziwa;D. Gandolfi;T. Guillot;E. Guenther;A. Léger;C. Moutou;M. Ollivier;T. Pasternacki;M. Patzold;H. Rauer;D. Rouan;A. Santerne;J. Schneider;G. W. A. M. Universit'e;Cnrs;Lam;Marseille;France.
第一个有测量半径的超级地球是CoRoT-7b，它开辟了岩石系外行星表征的新领域。为了更好地了解这个有趣的系统，CoRoT卫星进行了新的观测。在这次运行中，在成像模式下获得了90个新的凌日。这些数据与之前在发现运行中获得的151次凌日和HARPS径向速度观测结果一起进行了分析，以得出准确的系统参数。在之前的CoRoT运行（LRa01）和新的运行（LRa06）之间，发现了过境参数的后验概率分布的差异。我们认为这是由于先前的CoRoT运行中怀疑是过境点掩星事件的额外噪声成分造成的。这些导致平均凌日形状变成v形。我们表明，在低恒星通量水平下，额外的噪声成分占主导地位，并在最终分析中拒绝这些凌日。我们得到的行星半径Rp = 1.585±0.064 R⊕，与之前的估计一致。将行星半径与新的质量估计相结合，得出行星密度为1.19±0.27 ρ⊕，这与岩石组成相一致。CoRoT-7系统仍然是一个很好的测试平台，用于在浅凌日状态下推导行星参数的活动的影响。
The first super-Earth with measured radius discovered was CoRoT-7b and it has opened the new field of rocky exoplanet characterisation. To better understand this interesting system, new observations were taken with the CoRoT satellite. During this run 90 new transits were obtained in the imagette mode. These were analysed together with the previous 151 transits obtained in the discovery run and HARPS radial velocity observations to derive accurate system parameters. A difference is found in the posterior probability distribution of the transit parameters between the previous CoRoT run (LRa01) and the new run (LRa06). We propose that this is due to an extra noise component in the previous CoRoT run suspected of being transit spot occultation events. These lead to the mean transit shape becoming V-shaped. We show that the extra noise component is dominant at low stellar flux levels and reject these transits in the final analysis. We obtained a planetary radius, Rp = 1.585 ± 0.064 R⊕, in agreement with previous estimates. Combining the planetary radius with the new mass estimates results in a planetary density of 1.19 ± 0.27 ρ⊕ which is consistent with a rocky composition. The CoRoT-7 system remains an excellent test bed for the effects of activity in the derivation of planetary parameters in the shallow transit regime.