Techniques for Finding Close-in, Low-mass Planets around Evolved Intermediate-mass Stars
Techniques for Finding Close-in, Low-mass Planets around Evolved Intermediate-mass Stars
复制标题
寻找围绕演化的中等质量恒星的近距离低质量行星的技术
DOI：
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发表时间：
2018
影响因子：
4.9
通讯作者：
P. Cargile
中科院分区：
文献类型：
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作者：
A. Medina;J. Johnson;J. Eastman;P. Cargile
Jupiter-mass planets with large semimajor axes (a > 1.0 au) occur at a higher rate around evolved intermediate-mass stars. There is a pronounced paucity of close-in (a < 0.6 au), intermediate-period (5 < P < 100 days), low-mass (Mplanet < 0.7MJup ) planets, known as the “Planet Desert.” Current radial velocity (RV) methods have yet to yield close-in, low-mass planets around these stars because the planetary signals could be hidden by the (5–10) m s−1 RV variations caused by acoustic oscillations. We find that by implementing an observing strategy of taking three observations per night separated by an optimal Δt, which is a function of the oscillation periods and amplitudes, we can average over the stellar jitter and improve our sensitivity to low-mass planets. We find that Δt can be approximated using the stellar mass and radius given by the relationship Δt = 1.79 . We test our proposed method by injecting planets into well-sampled data of a subgiant star, γ Cep. We compare the fraction of planets recovered by our method to the fraction of planets recovered using current RV observational strategies. We find that our method decreases the rms of the stellar jitter due to acoustic oscillations by a factor of three over current single epoch observing strategies used for subgiant stars. Our observing strategy provides a means to test whether the Planet Desert extends to lower-mass planets.
影响因子：
6.5
作者：
A. Hatzes;M. Zechmeister;J. Matthews;R. Kuschnig;G. Walker;M. Doellinger;D. Guenther;A. Moffat;S. Rucinski;D. Sasselov
通讯作者：
A. Hatzes;M. Zechmeister;J. Matthews;R. Kuschnig;G. Walker;M. Doellinger;D. Guenther;A. Moffat;S. Rucinski;D. Sasselov