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Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multiepoch Vortex Coronagraphy Upper Limits

Llop-Sayson, Jorge and Wang, Jason J. and Ruffio, Jean-Baptiste and Mawet, Dimitri and Blunt, Sarah and Absil, Olivier and Bond, Charlotte and Brinkman, Casey and Bowler, Brendan P. and Bottom, Michael and Chontos, Ashley and Dalba, Paul A. and Fulton, B. J. and Giacalone, Steven and Hill, Michelle and Hirsch, Lea A. and Howard, Andrew W. and Isaacson, Howard and Karlsson, Mikael and Lubin, Jack and Madurowicz, Alex and Matthews, Keith and Morris, Evan and Perrin, Marshall and Ren, Bin and Rice, Malena and Rosenthal, Lee J. and Ruane, Garreth and Rubenzahl, Ryan and Sun, He and Wallack, Nicole and Xuan, Jerry W. and Ygouf, Marie (2021) Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multiepoch Vortex Coronagraphy Upper Limits. Astronomical Journal, 162 (5). Art. No. 181. ISSN 0004-6256. doi:10.3847/1538-3881/ac134a.

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ε Eridani is a young planetary system hosting a complex multibelt debris disk and a confirmed Jupiter-like planet orbiting at 3.48 au from its host star. Its age and architecture are thus reminiscent of the early Solar System. The most recent study of Mawet et al., which combined radial-velocity data and Ms-band direct imaging upper limits, started to constrain the planet's orbital parameters and mass, but are still affected by large error bars and degeneracies. Here we make use of the most recent data compilation from three different techniques to further refine epsilon Eridani b's properties: RVs, absolute astrometry measurements from the Hipparcos and Gaia missions, and new Keck/NIRC2 Ms-band vortex coronagraph images. We combine this data in a Bayesian framework. We find a new mass, M_b = 0.66_(-0.09)^(+0.12) MJup, and inclination, i = 78.81_(-22.41)^(+29.34), with at least a factor 2 of improvement over previous uncertainties. We also report updated constraints on the longitude of the ascending node, the argument of the periastron, and the time of periastron passage. With these updated parameters, we can better predict the position of the planet at any past and future epoch, which can greatly help define the strategy and planning of future observations and with subsequent data analysis. In particular, these results can assist the search for a direct detection with JWST and the Nancy Grace Roman Space Telescope's coronagraph instrument.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Llop-Sayson, Jorge0000-0002-3414-784X
Wang, Jason J.0000-0003-0774-6502
Ruffio, Jean-Baptiste0000-0003-2233-4821
Mawet, Dimitri0000-0002-8895-4735
Blunt, Sarah0000-0002-3199-2888
Absil, Olivier0000-0002-4006-6237
Brinkman, Casey0000-0002-4480-310X
Bowler, Brendan P.0000-0003-2649-2288
Bottom, Michael0000-0003-1341-5531
Chontos, Ashley0000-0003-1125-2564
Dalba, Paul A.0000-0002-4297-5506
Fulton, B. J.0000-0003-3504-5316
Giacalone, Steven0000-0002-8965-3969
Hill, Michelle0000-0002-0139-4756
Hirsch, Lea A.0000-0001-8058-7443
Howard, Andrew W.0000-0001-8638-0320
Isaacson, Howard0000-0002-0531-1073
Karlsson, Mikael0000-0002-2011-0851
Lubin, Jack0000-0001-8342-7736
Perrin, Marshall0000-0002-3191-8151
Ren, Bin0000-0003-1698-9696
Rice, Malena0000-0002-7670-670X
Rosenthal, Lee J.0000-0001-8391-5182
Ruane, Garreth0000-0003-4769-1665
Rubenzahl, Ryan0000-0003-3856-3143
Sun, He0000-0003-1526-6787
Wallack, Nicole0000-0003-0354-0187
Xuan, Jerry W.0000-0002-6618-1137
Ygouf, Marie0000-0001-7591-2731
Alternate Title:Constraining the Orbit and Mass of ε Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multi-epoch Vortex Coronagraphy Upper Limits
Additional Information:© 2021. The American Astronomical Society. Received 2021 May 11; revised 2021 June 22; accepted 2021 July 9; published 2021 October 6. This work was partially supported by the National Science Foundation AST-ATI Grant 1710210. The material is based upon work supported by NASA under award No. 80NSSC20K0624. J.J.W. is supported by the Heising-Simons Foundation 51 Pegasi b Fellowship. J.J.W. thanks Rob de Rosa and Eric Nielsen for helpful discussions. P.D. is supported by a National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1903811. M.R. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1752134 Part of this work has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 819155), and by the Wallonia-Brussels Federation (grant for Concerted Research Actions). We thank to Christopher Mendillo for useful discussions. Software: pyKLIP (Wang et al. 2015), Scipy(Jones et al. 2001), orbitize! (Blunt et al. 2020), emcee (Foreman-Mackey et al. 2013), (Foreman-Mackey 2016), RVSearch (Rosenthal et al. 2021), Astropy (Astropy Collaboration et al. 2013), Matplotlib (Hunter 2007).
Group:Astronomy Department
Funding AgencyGrant Number
Heising-Simons Foundation51 Pegasi b Fellowship
NSF Astronomy and Astrophysics FellowshipAST-1903811
NSF Graduate Research FellowshipDGE-1752134
European Research Council (ERC)819155
Wallonia-Brussels FederationUNSPECIFIED
Subject Keywords:Exoplanet astronomy; Exoplanets; Radial velocity; Astrometry; Direct imaging; Debris disks
Issue or Number:5
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanet astronomy (486); Exoplanets (498); Radial velocity (1332); Astrometry (80); Direct imaging (387); Debris disks (363)
Record Number:CaltechAUTHORS:20211012-211826814
Persistent URL:
Official Citation:Jorge Llop-Sayson et al 2021 AJ 162 181
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111368
Deposited By: George Porter
Deposited On:12 Oct 2021 22:15
Last Modified:13 Dec 2021 22:21

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