APOSTLE: LONGTERM TRANSIT MONITORING AND STABILITY ANALYSIS OF XO-2b

作者：Kundurthy P^*; Barnes R; Becker A C; Agol E; Williams B F; Gorelick N; Rose A

来源：Astrophysical Journal, 2013, 770(1): 36.

DOI：10.1088/0004-637X/770/1/36

• eclipses
• methods: numerical
• planetary systems
• planets and satellites: fundamental parameters
• planets and satellites: individual (XO-2b)

The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 10 transits of XO-2b over a period of 3 yr. We present measurements that confirm previous estimates of system parameters like the normalized semi-major axis (a/R-star), stellar density (rho(star)), impact parameter (b), and orbital inclination (i(orb)). Our errors on system parameters like a/R-star and rho(star) have improved by similar to 40% compared to previous best ground-based measurements. Our study of the transit times show no evidence for transit timing variations (TTVs) and we are able to rule out co-planar companions with masses >= 0.20 M-circle plus in low order mean motion resonance with XO-2b. We also explored the stability of the XO-2 system given various orbital configurations of a hypothetical planet near the 2:1 mean motion resonance. We find that a wide range of orbits (including Earth-mass perturbers) are both dynamically stable and produce observable TTVs. We find that up to 51% of our stable simulations show TTVs that are smaller than the typical transit timing errors (similar to 20 s) measured for XO-2b, and hence remain undetectable.

• 出版日期2013-6-10
• 单位Google Inc, Mountain View, CA