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A Nearby M Star with Three Transiting Super-Earths Discovered by K2

Crossfield, Ian J. M. and Howard, Andrew W. and Ciardi, David R. and de Kleer, Katherine and Christiansen, Jessie L. and Fulton, B. J. (2015) A Nearby M Star with Three Transiting Super-Earths Discovered by K2. Astrophysical Journal, 804 (1). Art. No. 10. ISSN 0004-637X.

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Small, cool planets represent the typical end-products of planetary formation. Studying the architectures of these systems, measuring planet masses and radii, and observing these planets' atmospheres during transit directly informs theories of planet assembly, migration, and evolution. Here we report the discovery of three small planets orbiting a bright (K_s = 8.6 mag) M0 dwarf using data collected as part of K2, the new ecliptic survey using the re-purposed Kepler spacecraft. Stellar spectroscopy and K2 photometry indicate that the system hosts three transiting planets with radii 1.5–2.1 R_⊕, straddling the transition region between rocky and increasingly volatile-dominated compositions. With orbital periods of 10–45 days the planets receive just 1.5–10× the flux incident on Earth, making these some of the coolest small planets known orbiting a nearby star; planet d is located near the inner edge of the system's habitable zone. The bright, low-mass star makes this system an excellent laboratory to determine the planets' masses via Doppler spectroscopy and to constrain their atmospheric compositions via transit spectroscopy. This discovery demonstrates the ability of K2 and future space-based transit searches to find many fascinating objects of interest.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Crossfield, Ian J. M.0000-0002-1835-1891
Howard, Andrew W.0000-0001-8638-0320
Ciardi, David R.0000-0002-5741-3047
de Kleer, Katherine0000-0002-9068-3428
Christiansen, Jessie L.0000-0002-8035-4778
Fulton, B. J.0000-0003-3504-5316
Additional Information:© 2015 The American Astronomical Society. Received 2015 January 15; Accepted 2015 February 16; Published 2015 April 23. We thank Geoff Marcy, Evan Sinukoff, and Charles Beichman for helpful conversations; Vishnu Reddy for swapping SpeX time; and Steve Bryson and our referee Don Pollacco for useful comments that improved the quality of this manuscript. A. W.H. acknowledges NASA grant No. NNX12AJ23G, and S.L. acknowledges NSF grant No. AST 09-08419. This work made use of the SIMBAD database (operated at CDS, Strasbourg, France); NASA’s Astrophysics Data System Bibliographic Services; the Authorea collaborative writing website; the NASA Exoplanet Archive; and Infrared Science Archive, and data products from the Two Micron All Sky Survey (2MASS), the APASS database, the SDSS-III project, the Digitized Sky Survey, and the Wide-Field Infrared Survey Explorer. Portions of this work were performed at the California Institute of Technology under contract with the National Aeronautics and Space Administration. Some of the data presented herein were obtained at the W. M. Keck Observatory (which is operated as a scientific partnership among Caltech, UC, and NASA) and at the Infrared Telescope Facility (IRTF, operated by UH under NASA contract NNH14CK55B). The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Facilities: APF (Levy), IRTF (SPEX), Keck: II (NIRC2), Kepler, NTT (EFOSC2)
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NSFAST 09-08419
Subject Keywords:eclipses; stars: individual (EPIC 201367065); techniques: photometric; techniques: spectroscopic
Issue or Number:1
Record Number:CaltechAUTHORS:20150604-125434670
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Official Citation:A Nearby M Star with Three Transiting Super-Earths Discovered by K2. Ian J. M. Crossfield et al. 2015 ApJ 804 10
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:58003
Deposited By: Joanne McCole
Deposited On:08 Jun 2015 21:07
Last Modified:14 Oct 2019 21:44

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