Revisiting a gravity-darkened and precessing planetary system PTFO 8-8695: spin-orbit non-synchronous case
| Autor: | Atsunori Yonehara, Tsubasa Nishioka, Shoya Kamiaka, Michisuke Tanaka, Risa Murakami, Yuxin Xue, Madoka Saitoh, Kento Masuda, K. Inayama, Yasushi Suto |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Earth and Planetary Astrophysics (astro-ph.EP) Gravity (chemistry) Space and Planetary Science Astronomy FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Earth and Planetary Astrophysics Planetary system Orbit (control theory) Astrophysics - Earth and Planetary Astrophysics Spin-½ |
| DOI: | 10.48550/arxiv.1506.04829 |
| Popis: | We reanalyse the time-variable lightcurves of the transiting planetary system PTFO 8-8695, in which a planet of 3 to 4 Jupiter mass orbits around a rapidly rotating pre-main-sequence star. Both the planetary orbital period of 0.448 days and the stellar spin period less than 0.671 days are unusually short, which makes PTFO 8-8695 an ideal system to check the model of gravity darkening and nodal precession. While the previous analysis of PTFO 8-8695 assumed that the stellar spin and planetary orbital periods are the same, we extend the analysis by discarding the spin-orbit synchronous condition, and find three different classes of solutions roughly corresponding to the nodal precession periods of 199$\pm$16, 475$\pm$21, and 827$\pm$53 days that reproduce the transit lightcurves observed in 2009 and 2010. We compare the predicted lightcurves of the three solutions against the photometry data of a few percent accuracy obtained at Koyama Astronomical Observatory in 2014 and 2015, and find that the solution with the precession period of 199$\pm$16 days is preferred even though preliminary. Future prospect and implications to other transiting systems are briefly discussed. Comment: 9 pages, 6 Figures, 2 Tables, accepted for publication in PASJ |
| Databáze: | OpenAIRE |
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