A long-period substellar object exhibiting a single transit in Kepler
Abstract
We report the detection of a single transit-like signal in the Kepler data of the slightly evolved F star KIC4918810. The transit duration is ~45 hours, and while the orbital period (P ∼10 years) is not well constrained, it is one of the longest among companions known to transit. We calculate the size of the transiting object to be R_P = 0.910 R_J. Objects of this size vary by orders of magnitude in their densities, encompassing masses between that of Saturn (0.3 M_J) and stars above the hydrogen-burning limit (~80 M_J). Radial-velocity observations reveal that the companion is unlikely to be a star. The mass posterior is bimodal, indicating a mass of either ~0.24 M_J or ~26 M_J. Continued spectroscopic monitoring should either constrain the mass to be planetary or detect the orbital motion, the latter of which would yield a benchmark long-period brown dwarf with a measured mass, radius, and age.
Additional Information
Attribution 4.0 International (CC BY 4.0) This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This work has also made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This research has made use of NASA's Astrophysics Data System Bibliographic Services. Facilities: Kepler, FLWO:1.5m (TRES), Keck:I (HIRES), Gaia Software: EXOFASTv2 (Eastman 2017; Eastman et al. 2019)Attached Files
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Additional details
- Eprint ID
- 111514
- Resolver ID
- CaltechAUTHORS:20211018-185204670
- NAS 5-26555
- NASA
- Gaia Multilateral Agreement
- W. M. Keck Foundation
- Created
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2021-10-19Created from EPrint's datestamp field
- Updated
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2023-06-02Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department