تقرير
Characterising TOI-732 b and c: new insights on the M-dwarf radius and density valley
| العنوان: | Characterising TOI-732 b and c: new insights on the M-dwarf radius and density valley |
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| المؤلفون: | Bonfanti, A., Brady, M., Wilson, T. G., Venturini, J., Egger, J. A., Brandeker, A., Sousa, S. G., Lendl, M., Simon, A. E., Queloz, D., Olofsson, G., Adibekyan, V., Alibert, Y., Fossati, L., Hooton, M. J., Kubyshkina, D., Luque, R., Murgas, F., Mustill, A. J., Santos, N. C., Van Grootel, V., Alonso, R., Asquier, J., Bandy, T., Bárczy, T., Navascues, D. Barrado, Barros, S. C. C., Baumjohann, W., Bean, J., Beck, M., Beck, T., Benz, W., Bergomi, M., Billot, N., Borsato, L., Broeg, C., Cameron, A. Collier, Csizmadia, Sz., Cubillos, P. E., Davies, M. B., Deleuil, M., Deline, A., Delrez, L., Demangeon, O. D. S., Demory, B. -O., Ehrenreich, D., Erikson, A., Fortier, A., Fridlund, M., Gandolfi, D., Gillon, M., Güdel, M., Günther, M. N., Heitzmann, A., Helling, Ch., Hoyer, S., Isaak, K. G., Kasper, D., Kiss, L. L., Lam, K. W. F., Laskar, J., Etangs, A. Lecavelier des, Magrin, D., Maxted, P. F. L., Mordasini, C., Nascimbeni, V., Ottensamer, R., Pagano, I., Pallé, E., Peter, G., Piotto, G., Pollacco, D., Ragazzoni, R., Rando, N., Rauer, H., Ribas, I., Scandariato, G., Ségransan, D., Seifahrt, A., Smith, A. M. S., Stalport, M., Stefánsson, G., Steinberger, M., Stürmer, J., Szabó, Gy. M., Thomas, N., Udry, S., Villaver, E., Walton, N. A., Westerdorff, K., Zingales, T. |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Earth and Planetary Astrophysics |
| الوصف: | TOI-732 is an M dwarf hosting two transiting planets, which are located on the two opposite sides of the radius valley. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also aim at using the results to study the slope of both the radius valley and the density valley for a well characterised sample of M dwarf exoplanets. We performed a global MCMC analysis by jointly modelling ground-based light curves, CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M dwarf valleys were quantified via a Support Vector Machine (SVM) procedure. TOI-732 b is an ultra short period planet ($P\sim0.77$ d) with a radius $R_b=1.325_{-0.058}^{+0.057}$ $R_{\oplus}$ and a mass $M_b=2.46\pm0.19$ $M_{\oplus}$ (mean density $\rho_b=5.8_{-0.8}^{+1.0}$ g cm$^{-3}$), while the outer planet at $P\sim12.25$ d has $R_c=2.39_{-0.11}^{+0.10}$ $R_{\oplus}$, $M_c=8.04_{-0.48}^{+0.50}$ $M_{\oplus}$, and thus $\rho_c=3.24_{-0.43}^{+0.55}$ g cm$^{-3}$. Also considering our interior structure calculations TOI-732 b is a super-Earth and TOI-732 c is a mini-Neptune. Following the SVM approach, we quantified $\mathrm{d}\log{R_{p,{\mathrm{valley}}}}/\mathrm{d}\log{P}=-0.065_{-0.013}^{+0.024}$, which is flatter than for Sun-like stars. In line with former analyses, we noted a more filled radius valley for M-planets and we further quantified the density valley slope as $\mathrm{d}\log{\hat{\rho}_{\mathrm{valley}}}/\mathrm{d}\log{P}=-0.02_{-0.04}^{+0.12}$. Compared to FGK stars, the weaker dependence of the position of the radius valley with orbital period might indicate a heavier influence of formation relative to evolution mechanisms in shaping the radius valley around M-dwarfs. Comment: 28 pages (17 in the main text), 18 figures (9 in the main text), 11 tables (7 in the main text). Accepted for publication in A&A |
| نوع الوثيقة: | Working Paper |
| الوصول الحر: | http://arxiv.org/abs/2311.12577Test |
| رقم الانضمام: | edsarx.2311.12577 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |