Transiting extrasolar planetary candidates in the Galactic bulge

Abstract

More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to the reflex motions of their host stars, and more recently through transits of some planets across the face of the host stars. The detection of planets with the shortest known periods, 1.2 to 2.5 days, has mainly resulted from transit surveys which have generally targeted stars more massive than 0.75 M_sun. Here we report the results from a planetary transit search performed in a rich stellar field towards the Galactic bulge. We discovered 16 candidates with orbital periods between 0.4 and 4.2 days, five of which orbit stars of 0.44 to 0.75 M_sun. In two cases, radial-velocity measurements support the planetary nature of the companions. Five candidates have orbital periods below 1.0 day, constituting a new class of ultra-short-period planets (USPPs), which occur only around stars of less than 0.88 M_sun. This indicates that those orbiting very close to more luminous stars might be evaporatively destroyed, or that jovian planets around lower-mass stars might migrate to smaller radii.

To appear in October 5, 2006 issue of Nature

References in corpus (1)

• TrES-1: The Transiting Planet of a Bright K0V Star

Cited by in corpus (15)

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• Extrasolar Giant Planets and X-ray Activity
• The Bulge Radial Velocity Assay (BRAVA): I. Sample Selection and a Rotation Curve
• Using Transit Timing Observations to Search for Trojans of Transiting Extrasolar Planets
• The Frequency of Large Radius Hot and Very Hot Jupiters in omega Centauri
• Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates III: Accurate Radius and Period for OGLE-TR-111-b
• Deep MMT Transit Survey of the Open Cluster M37 IV: Limit on the Fraction of Stars With Planets as Small as 0.3 R_J
• Looking for Super-Earths in the HD 189733 System: A Search for Transits in Most Space-Based Photometry
• Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates: II. Transits of OGLE-TR-113-b in the Optical and Near-IR
• Photometric Oscillations of Low Luminosity Red Giant Stars
• The WFC3 Galactic Bulge Treasury Program: A First Look at Resolved Stellar Population Tools
• SuperWASP-North Extra-solar Planet Candidates between 3hr < RA < 6hr
• The Galactic Bulge: A Review
• Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates IV: The Puzzle of the Extremely Red OGLE-TR-82 Primary Solved