Observational Constraints on Trojans of Transiting Extrasolar Planets

Abstract

Theoretical studies predict that Trojans are likely a frequent byproduct of planet formation and evolution. We present a novel method of detecting Trojan companions to transiting extrasolar planets which involves comparing the time of central eclipse with the time of the stellar reflex velocity null. We demonstrate that this method offers the potential to detect terrestrial-mass Trojans using existing ground-based observatories. This method rules out Trojan companions to HD 209458b and HD 149026b more massive than ~13 Earth masses and \~25 Earth masses at a 99.9% confidence level. Such a Trojan would be dynamically stable, would not yet have been detected by photometric or spectroscopic monitoring, and would be unrecognizable from radial velocity observations alone. We outline the future prospects for this method, and show that the detection of a "Hot Trojan" of any mass would place a significant constraint on theories of orbital migration.

6 pages, 2 figures, 1 table, accepted to ApJL. Added references, new transiting planets to table; minor corrections

References in corpus (4)

• TrES-1: The Transiting Planet of a Bright K0V Star
• A Transiting Planet of a Sun-like Star
• Transit Photometry of the Core-Dominated Planet HD 149026b
• Could the 47 UMa Planetary System be a Second Solar System: predicting the Earth-like planets

Cited by in corpus (14)

• Origins of Eccentric Extrasolar Planets: Testing the Planet-Planet Scattering Model
• Determination of the size, mass, and density of "exomoons" from photometric transit timing variations
• Using Transit Timing Observations to Search for Trojans of Transiting Extrasolar Planets
• Characterizing the Orbital Eccentricities of Transiting Extrasolar Planets with Photometric Observations
• A transit timing analysis of nine RISE light curves of the exoplanet system TrES-3
• On the extrasolar multi-planet system around HD160691
• A Tentative Detection of a Starspot During Consecutive Transits of an Extrasolar Planet from the Ground: No Evidence of a Double Transiting Planet System Around TrES-1
• The Secular Evolution and Dynamical Architecture of the Neptunian Triplet Planetary System HD 69830
• Secondary resonances of co-orbital motions
• Looking for Super-Earths in the HD 189733 System: A Search for Transits in Most Space-Based Photometry
• On the growth and stability of Trojan planets
• Measuring accurate transit parameters
• A Search for Exotrojans in Transiting Exoplanetary systems
• Habitable Zones for Earth-mass Planets in Multiple Planetary Systems