A Caltech Library Service

Two Small Transiting Planets and a Possible Third Body Orbiting HD 106315

Crossfield, Ian J. M. and Ciardi, David R. and Isaacson, Howard and Howard, Andrew W. and Petigura, Erik A. and Weiss, Lauren M. and Fulton, Benjamin J. and Sinukoff, Evan and Schlieder, Joshua E. and Mawet, Dimitri and Ruane, Garreth and de Pater, Imke and de Kleer, Katherine and Davies, Ashley G. and Christiansen, Jessie L. and Dressing, Courtney D. and Hirsch, Lea and Benneke, Björn and Crepp, Justin R. and Kosiarek, Molly and Livingston, John and Gonzales, Erica and Beichman, Charles A. and Knutson, Heather A. (2017) Two Small Transiting Planets and a Possible Third Body Orbiting HD 106315. Astronomical Journal, 153 (6). Art. No. 255. ISSN 1538-3881. doi:10.3847/1538-3881/aa6e01.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


The masses, atmospheric makeups, spin–orbit alignments, and system architectures of extrasolar planets can be best studied when the planets orbit bright stars. We report the discovery of three bodies orbiting HD 106315, a bright (V = 8.97 mag) F5 dwarf targeted by our K2 survey for transiting exoplanets. Two small transiting planets are found to have radii 2.23^(+0.30)_(-0.25)R⊕ and 3.95^(+0.42)_(-0.39)R⊕ and orbital periods 9.55 days and 21.06 days, respectively. A radial velocity (RV) trend of 0.3 ± 0.1 m s^(−1) day^(−1) indicates the likely presence of a third body orbiting HD 106315 with period ≳160 days and mass ≳45 M⊕. Transits of this object would have depths ≳0.1% and are definitively ruled out. Although the star has v sin i = 13.2 km s^(−1), it exhibits a short-timescale RV variability of just 6.4 m s^(−1). Thus, it is a good target for RV measurements of the mass and density of the inner two planets and the outer object's orbit and mass. Furthermore, the combination of RV noise and moderate v sin i makes HD 106315 a valuable laboratory for studying the spin–orbit alignment of small planets through the Rossiter–McLaughlin effect. Space-based atmospheric characterization of the two transiting planets via transit and eclipse spectroscopy should also be feasible. This discovery demonstrates again the power of K2 to find compelling exoplanets worthy of future study.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Crossfield, Ian J. M.0000-0002-1835-1891
Ciardi, David R.0000-0002-5741-3047
Isaacson, Howard0000-0002-0531-1073
Howard, Andrew W.0000-0001-8638-0320
Petigura, Erik A.0000-0003-0967-2893
Weiss, Lauren M.0000-0002-3725-3058
Fulton, Benjamin J.0000-0003-3504-5316
Sinukoff, Evan0000-0002-5658-0601
Schlieder, Joshua E.0000-0001-5347-7062
Mawet, Dimitri0000-0002-8895-4735
Ruane, Garreth0000-0003-4769-1665
de Pater, Imke0000-0002-4278-3168
de Kleer, Katherine0000-0002-9068-3428
Davies, Ashley G.0000-0003-1747-8142
Christiansen, Jessie L.0000-0002-8035-4778
Dressing, Courtney D.0000-0001-8189-0233
Hirsch, Lea0000-0001-8058-7443
Benneke, Björn0000-0001-5578-1498
Crepp, Justin R.0000-0003-0800-0593
Kosiarek, Molly0000-0002-6115-4359
Beichman, Charles A.0000-0002-5627-5471
Knutson, Heather A.0000-0002-0822-3095
Additional Information:© 2017 The American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2017 January 13; revised 2017 February 13; accepted 2017 February 15; published 2017 May 19. This work made use of the SIMBAD database (operated at CDS, Strasbourg, France) and NASA's Astrophysics Data System Bibliographic Services. This research has made use of the NASA Exoplanet Archive and the Infrared Science Archive, which are operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration. 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 WM Keck Observatory (which is operated as a scientific partnership among Caltech, UC, and NASA). 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. I.J.M.C. was supported for this work under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. A.W.H. acknowledges support for this K2 work from a NASA Astrophysics Data Analysis Program grant, support from the K2 Guest Observer Program, and a NASA Key Strategic Mission Support Project. L.M.W. acknowledges support from the Trottier family. Facility: Kepler, Keck-II (NIRC2), Keck-II (HIRES). Note added in review: While preparing this paper, we became aware of another paper describing the identification of HD 106315 as a planet-hosing system (Rodriguez et al. 2017). We are pleased that both groups report consistent results despite the fact that no detailed information was shared prior to submission of the two papers.
Group:Infrared Processing and Analysis Center (IPAC), Astronomy Department
Funding AgencyGrant Number
Trottier Family FoundationUNSPECIFIED
Subject Keywords:eclipses – stars: individual (HD 106315) – techniques: photometric – techniques: spectroscopi
Issue or Number:6
Record Number:CaltechAUTHORS:20170619-123025887
Persistent URL:
Official Citation:Ian J. M. Crossfield et al 2017 AJ 153 255
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78330
Deposited By: Tony Diaz
Deposited On:19 Jun 2017 20:10
Last Modified:15 Nov 2021 17:38

Repository Staff Only: item control page