دورية أكاديمية
CHEOPS observations of KELT-20 b/MASCARA-2 b: An aligned orbit and signs of variability from a reflective day side
| العنوان: | CHEOPS observations of KELT-20 b/MASCARA-2 b: An aligned orbit and signs of variability from a reflective day side |
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| المؤلفون: | Singh, V., Scandariato, G., Smith, A. M. S., Cubillos, P. E., Lendl, M., Billot, N., Fortier, A., Queloz, D., Sousa, S. G., Csizmadia, Sz., Brandeker, A., Carone, L., Wilson, T. G., Akinsanmi, B., Patel, J. A., Krenn, A., Demangeon, O. D. S., Bruno, G., Pagano, I., Hooton, M. J., Cabrera, J., Santos, N. C., Alibert, Y., Alonso, R., Asquier, J., Bárczy, T., Navascues, D. Barrado, Barros, S. C. C., Baumjohann, W., Beck, M., Beck, T., Benz, W., Bergomi, M., Bonfanti, A., Bonfils, X., Borsato, L., Broeg, C., Charnoz, S., Cameron, A. Collier, Davies, M. B., Deleuil, M., Deline, A., Delrez, L., Demory, B.-O., Ehrenreich, D., Erikson, A., Fossati, L., Fridlund, M., Gandolfi, D., Gillon, M., Güdel, M., Günther, M. N., Harre, J.-V., Heitzmann, A., Helling, Ch., Hoyer, S., Isaak, K. G., Kiss, L. L., Lam, K. W. F., Laskar, J., des Etangs, A. Lecavelier, Magrin, D., Maxted, P. F. L., Mischler, H., Mordasini, C., Nascimbeni, V., Olofsson, G., Ottensamer, R., Pallé, E., Peter, G., Piotto, G., Pollacco, D., Ragazzoni, R., Rando, N., Rauer, H., Ribas, I., Salmon, S., Ségransan, D., Simon, A. E., Stalport, M., Steinberger, M., Szabó, Gy. M., Thomas, N., Udry, S., Ulmer, B., Van Grootel, V., Venturini, J., Villaver, E., Walton, N. A., Zingales, T. |
| المصدر: | Singh, V.; Scandariato, G.; Smith, A. M. S.; Cubillos, P. E.; Lendl, M.; Billot, N.; Fortier, A.; Queloz, D.; Sousa, S. G.; Csizmadia, Sz.; Brandeker, A.; Carone, L.; Wilson, T. G.; Akinsanmi, B.; Patel, J. A.; Krenn, A.; Demangeon, O. D. S.; Bruno, G.; Pagano, I.; Hooton, M. J.; . (2024). CHEOPS observations of KELT-20 b/MASCARA-2 b: An aligned orbit and signs of variability from a reflective day side. Astronomy and astrophysics, 683 EDP Sciences 10.1051/0004-6361/202347533 |
| بيانات النشر: | EDP Sciences |
| سنة النشر: | 2024 |
| المجموعة: | BORIS (Bern Open Repository and Information System, University of Bern) |
| مصطلحات موضوعية: | 500 Science, 520 Astronomy, 530 Physics, 620 Engineering |
| الوصف: | Context. Occultations are windows of opportunity to indirectly peek into the dayside atmosphere of exoplanets. High-precision transit events provide information on the spin-orbit alignment of exoplanets around fast-rotating hosts. Aims. We aim to precisely measure the planetary radius and geometric albedo of the ultra-hot Jupiter (UHJ) KELT-20 b along with the spin-orbit alignment of the system. Methods. We obtained optical high-precision transits and occultations of KELT-20 b using CHEOPS observations in conjunction with simultaneous TESS observations. We interpreted the occultation measurements together with archival infrared observations to measure the planetary geometric albedo and dayside temperatures. We further used the host star’s gravity-darkened nature to measure the system’s obliquity. Results. We present a time-averaged precise occultation depth of 82 ± 6 ppm measured with seven CHEOPS visits and 131−7+8 from the analysis of all available TESS photometry. Using these measurements, we precisely constrain the geometric albedo of KELT-20 b to 0.26 ± 0.04 and the brightness temperature of the dayside hemisphere to 2566−80+77 K. Assuming Lambertian scattering law, we constrain the Bond albedo to 0.36−0.05+0.04 along with a minimal heat transfer to the night side (ϵ = 0.14−0.10+0.13). Furthermore, using five transit observations we provide stricter constraints of 3 9 ± 1 1 deg on the sky-projected obliquity of the system. Conclusions. The aligned orbit of KELT-20 b is in contrast to previous CHEOPS studies that have found strongly inclined orbits for planets orbiting other A-type stars. The comparably high planetary geometric albedo of KELT-20 b corroborates a known trend of strongly irradiated planets being more reflective. Finally, we tentatively detect signs of temporal variability in the occultation depths, which might indicate variable cloud cover advecting onto the planetary day side. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| العلاقة: | https://boris.unibe.ch/195659Test/ |
| الإتاحة: | https://doi.org/10.1051/0004-6361/202347533Test https://boris.unibe.ch/195659/1/aa47533-23.pdfTest https://boris.unibe.ch/195659Test/ |
| حقوق: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.D73E30AC |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |