A Caltech Library Service

Deep Exploration of ϵ Eridani with Keck Ms-band Vortex Coronagraphy and Radial Velocities: Mass and Orbital Parameters of the Giant Exoplanet

Mawet, Dimitri and Hirsch, Lea and Lee, Eve J. and Ruffio, Jean-Baptiste and Bottom, Michael and Fulton, Benjamin J. and Absil, Olivier and Beichman, Charles and Bowler, Brendan and Bryan, Marta and Choquet, Élodie and Ciardi, David and Christiaens, Valentin and Defrère, Denis and Gomez Gonzalez, Carlos Alberto and Howard, Andrew W. and Huby, Elsa and Isaacson, Howard and Jensen-Clem, Rebecca and Kosiarek, Molly and Marcy, Geoff and Meshkat, Tiffany and Petigura, Erik and Reggiani, Maddalena and Ruane, Garreth and Serabyn, Eugene and Sinukoff, Evan and Wang, Ji and Weiss, Lauren and Ygouf, Marie (2019) Deep Exploration of ϵ Eridani with Keck Ms-band Vortex Coronagraphy and Radial Velocities: Mass and Orbital Parameters of the Giant Exoplanet. Astronomical Journal, 157 (1). Art. No. 33. ISSN 1538-3881. doi:10.3847/1538-3881/aaef8a.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present the most sensitive direct imaging and radial velocity (RV) exploration of epsilon Eridani to date. epsilon Eridani is an adolescent planetary system, reminiscent of the early solar system. It is surrounded by a prominent and complex debris disk that is likely stirred by one or several gas giant exoplanets. The discovery of the RV signature of a giant exoplanet was announced 15 yr ago, but has met with scrutiny due to possible confusion with stellar noise. We confirm the planet with a new compilation and analysis of precise RV data spanning 30 yr, and combine it with upper limits from our direct imaging search, the most sensitive ever performed. The deep images were taken in the Ms band (4.7 μm) with the vortex coronagraph recently installed in W.M. Keck Observatory's infrared camera NIRC2, which opens a sensitive window for planet searches around nearby adolescent systems. The RV data and direct imaging upper limit maps were combined in an innovative joint Bayesian analysis, providing new constraints on the mass and orbital parameters of the elusive planet. epsilon Eridani b has a mass of 0.78_(-0.12)^(+0.38} M_(Jup) and is orbiting epsilon Eridani at about 3.48 ± 0.02 au with a period of 7.37 ± 0.07 yr. The eccentricity of epsilon Eridani b's orbit is 0.07_(-0.05)^(+0.06), an order of magnitude smaller than early estimates and consistent with a circular orbit. We discuss our findings from the standpoint of planet–disk interactions and prospects for future detection and characterization with the James Webb Space Telescope.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Mawet, Dimitri0000-0002-8895-4735
Hirsch, Lea0000-0001-8058-7443
Lee, Eve J.0000-0002-1228-9820
Ruffio, Jean-Baptiste0000-0003-2233-4821
Bottom, Michael0000-0003-1341-5531
Fulton, Benjamin J.0000-0003-3504-5316
Absil, Olivier0000-0002-4006-6237
Beichman, Charles0000-0002-5627-5471
Bowler, Brendan0000-0003-2649-2288
Bryan, Marta0000-0002-6076-5967
Choquet, Élodie0000-0002-9173-0740
Ciardi, David0000-0002-5741-3047
Christiaens, Valentin0000-0002-0101-8814
Defrère, Denis0000-0003-3499-2506
Gomez Gonzalez, Carlos Alberto0000-0003-2050-1710
Howard, Andrew W.0000-0001-8638-0320
Isaacson, Howard0000-0002-0531-1073
Jensen-Clem, Rebecca0000-0003-0054-2953
Kosiarek, Molly0000-0002-6115-4359
Marcy, Geoff0000-0002-2909-0113
Meshkat, Tiffany0000-0001-6126-2467
Petigura, Erik0000-0003-0967-2893
Reggiani, Maddalena0000-0003-2911-0898
Ruane, Garreth0000-0003-4769-1665
Sinukoff, Evan0000-0002-5658-0601
Wang, Ji0000-0002-4361-8885
Weiss, Lauren0000-0002-3725-3058
Ygouf, Marie0000-0001-7591-2731
Additional Information:© 2019. The American Astronomical Society. Received 2018 May 1; revised 2018 October 16; accepted 2018 October 29; published 2019 January 3. The authors would like to acknowledge the contributions and useful comments from Prof. Debra Fischer and Prof. James Graham. 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 (NASA). 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 work was partially performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. (C) 2017. All rights reserved. E.C. acknowledges support from NASA through Hubble Fellowship grant HF2-51355 awarded by STScI, which is operated by AURA, Inc. for NASA under contract NAS5-26555. We also acknowledge support from NASA/NExSS through grant no. NNX15AD95G. Software: RadVel (Fulton et al. 2018), emcee (Foreman-Mackey et al. 2013), VIP (Gomez Gonzalez et al. 2017), PyKLIP (Wang et al. 2015).
Group:Infrared Processing and Analysis Center (IPAC), TAPIR, Walter Burke Institute for Theoretical Physics, Astronomy Department
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
NASA Hubble FellowshipHF2-51355
Fonds de la Recherche Scientifique (FNRS)UNSPECIFIED
Miller Institute for Basic Research in ScienceUNSPECIFIED
NSF Graduate Research FellowshipUNSPECIFIED
NSF Astronomy and Astrophysics FellowshipUNSPECIFIED
Subject Keywords:planet–disk interactions; planets and satellites: dynamical evolution and stability; planets and satellites: gaseous planets; planetary systems; techniques: high angular resolution; techniques: radial velocities
Issue or Number:1
Record Number:CaltechAUTHORS:20190103-105531269
Persistent URL:
Official Citation:Dimitri Mawet et al 2019 AJ 157 33
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92031
Deposited By: George Porter
Deposited On:03 Jan 2019 19:08
Last Modified:16 Nov 2021 03:46

Repository Staff Only: item control page