On the detection of Exomoons: A search in Kepler data for the orbital sampling effect and the scatter peak

Abstract

Despite the discovery of thousands of exoplanets, no exomoons have been detected so far. We test a recently developed method for exomoon search, the orbital sampling effect (OSE), using the full exoplanet photometry from the Kepler Space Telescope. The OSE is applied to phase-folded transits, for which we present a framework to detect false positives, and discuss four candidates which pass several of our tests. Using numerical simulations, we inject exomoon signals into real Kepler data and retrieve them, showing that under favorable conditions, exomoons can be found with Kepler and the OSE method. In addition, we super-stack a large sample of Kepler planets to search for the average exomoon OSE and the accompanying increase in noise, the scatter peak. We find a significant OSE-like signal, which might indicate the presence of moons, for planets with 35d<P<80d, having an average dip per planet of 6+-2ppm, corresponding to a moon radius of 2120 +330 -370km for the average star radius of 1.24R_Sun in this sample.

ApJ accepted. 24 pages, 26 Figures. Supplementary material at this http URL http://jaekle.info/ose/

References in corpus (10)

• Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by exomoons?
• SOPHIE velocimetry of Kepler transit candidates XII. KOI-1257 b: a highly eccentric three-month period transiting exoplanet
• A novel method for identifying exoplanetary rings
• Detecting extrasolar moons akin to solar system satellites with an orbital sampling effect
• Parallaxes of Star Forming Regions in the Outer Spiral Arm of the Milky Way
• Kepler423b: a half-Jupiter mass planet transiting a very old solar-like star
• How to determine an exomoon's sense of orbital motion
• The Effect of Planetary Illumination on Climate Modelling of Earthlike Exomoons
• The Possible Moon of Kepler-90g is a False Positive
• Observation of flux tube crossings in the solar wind

Cited by in corpus (6)

• HEK VI: On the Dearth of Galilean Analogs in Kepler and the Exomoon Candidate Kepler-1625b I
• No Evidence for Lunar Transit in New Analysis of Hubble Space Telescope Observations of the Kepler-1625 System
• On The Feasibility of Exomoon Detection Via Exoplanet Phase Curve Spectral Contrast
• Formation of Exomoons: A Solar System Perspective
• Refraction in exoplanet atmospheres: Photometric signatures, implications for transmission spectroscopy, and search in Kepler data
• Why exomoons must be rare?