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Title: The hunt for exomoons with Kepler (HEK). IV. A search for moons around eight M dwarfs

With their smaller radii and high cosmic abundance, transiting planets around cool stars hold a unique appeal. As part of our ongoing project to measure the occurrence rate of extrasolar moons, in this work we present results from a survey focusing on eight Kepler planetary candidates associated with M dwarfs. Using photodynamical modeling and Bayesian multimodal nested sampling, we find no compelling evidence for an exomoon in these eight systems. Upper limits on the presence of such bodies probe down to masses of ∼0.4 M {sub ⊕} in the best case. For KOI-314, we are able to confirm the planetary nature of two out of the three known transiting candidates using transit timing variations. Of particular interest is KOI-314c, which is found to have a mass of 1.0{sub −0.3}{sup +0.4} M {sub ⊕}, making it the lowest mass transiting planet discovered to date. With a radius of 1.61{sub −0.15}{sup +0.16} R {sub ⊕}, this Earth-mass world is likely enveloped by a significant gaseous envelope comprising ≥17{sub −13}{sup +12}% of the planet by radius. We also find evidence to support the planetary nature of KOI-784 via transit timing, but we advocate further observations to verify the signals. In both systems, wemore » infer that the inner planet has a higher density than the outer world, which may be indicative of photo-evaporation. These results highlight both the ability of Kepler to search for sub-Earth-mass moons and the exciting ancillary science that often results from such efforts.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [4] ;
  1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
  2. Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)
  3. Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)
  4. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States)
Publication Date:
OSTI Identifier:
22351512
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; DENSITY; DETECTION; EARTH PLANET; EVAPORATION; GLOBAL ASPECTS; MASS; MOON; PROBES; SAMPLING; STARS