English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

PTFO 8-8695b represents the first transiting exoplanet candidate orbiting apre-main-sequence star. We find that the unusual lightcurve shapes of PTFO8-8695 can be explained by transits of a planet across an oblate,gravity-darkened stellar disk. We simultaneously and self-consistently fit twoseparate lightcurves observed in 2009 December and 2010 December. Our twoself-consistent fits yield M_p = 3.0 M_Jup and M_p = 3.6 M_Jup for assumedstellar masses of M_* = 0.34 M_Sun and M_* = 0.44 M_Sun respectively. The twofits have precession periods of 293 days and 581 days. These massdeterminations (consistent with previous upper limits) along with the strengthof the gravity-darkened precessing model together validate PTFO 8-8695b as justthe second Hot Jupiter known to orbit an M-dwarf. Our fits show a high degreeof spin-orbit misalignment in the PTFO 8-8695 system: 69 +/- 2 or 73.1 +/- 0.5degrees, in the two cases. The large misalignment is consistent with thehypothesis that planets become Hot Jupiters with random orbital planealignments early in a system's lifetime. We predict that as a result of thehighly misaligned, precessing system, the transits should disappear for monthsat a time over the course of the system's precession period. The precessing,gravity-darkened model also predicts other observable effects: changing orbitinclination that could be detected by radial velocity observations, changingstellar inclination that would manifest as varying v sin i, changing projectedspin-orbit alignment that could be seen by the Rossiter-McLaughlin effect,changing transit shapes over the course of the precession, and differinglightcurves as a function of wavelength. Our measured planet radii of 1.64R_Jup and 1.68 R_Jup in each case are consistent with a young,hydrogen-dominated planet that results from a hot-start formation mechanism.

Measurement of Spin-Orbit Misalignment and Nodal Precession for the Planet around Pre-Main-Sequence Star PTFO 8-8695 From Gravity Darkening