A Caltech Library Service

Direct Imaging of Exoplanets beyond the Radial Velocity Limit: Application to the HD 134987 System

Li, Zhexing and Hildebrandt, Sergi R. and Kane, Stephen R. and Zimmerman, Neil T. and Girard, Julien H. and Gonzalez-Quiles, Junellie and Turnbull, Margaret C. (2021) Direct Imaging of Exoplanets beyond the Radial Velocity Limit: Application to the HD 134987 System. Astronomical Journal, 162 (1). Art. No. 9. ISSN 0004-6256. doi:10.3847/1538-3881/abf831.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


Future direct imaging missions will primarily observe planets that have been previously detected, mostly via the radial velocity (RV) technique, to characterize planetary atmospheres. In the meantime, direct imaging may discover new planets within existing planetary systems that have bright enough reflected flux but insufficient signals for other methods to detect. Here we investigate the parameter space within which planets are unlikely to be detected by RV in the near future due to precision limitations but could be discovered through reflected light with future direct imaging missions. We use the HD 134987 system as a working example, combine RV and direct imaging detection limit curves in the same parameter space through various assumptions, and insert a fictitious planet into the system while ensuring that it lies between the RV and imaging detection limits. Planet validity tested through dynamical simulations and retrieval tests revealed that the planet could indeed be detected by imaging while remaining hidden from RV surveys. Direct imaging retrieval was carried out using starshade simulations for two mission concepts: the Starshade Rendezvous Probe, which could be coupled with the Nancy Grace Roman Space Telescope, and the Habitable Exoplanet Observatory. This method is applicable to all other systems and high-contrast direct imaging instruments and could help inform future imaging observations and data analysis on the discovery of new exoplanets.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper ItemCode
Li, Zhexing0000-0002-4860-7667
Hildebrandt, Sergi R.0000-0003-0220-0009
Kane, Stephen R.0000-0002-7084-0529
Zimmerman, Neil T.0000-0001-5484-1516
Girard, Julien H.0000-0001-8627-0404
Gonzalez-Quiles, Junellie0000-0002-9032-8530
Turnbull, Margaret C.0000-0002-0569-1643
Additional Information:© 2021. The American Astronomical Society. Received 2020 December 11; revised 2021 April 12; accepted 2021 April 13; published 2021 June 9. The authors would like to thank Chris Stark for sharing an improved version of ZODIPIC, which was used to generate the input exozodiacal dust in Section 4.2.2. The authors wish to also thank the referee for providing a swift and valuable response that greatly improved the presentation of this work. This work was funded by the Roman CGI Science Investigation Team contract #NNG16P27C (PI: Margaret Turnbull). This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Dynamical simulations in this paper made use of the REBOUND code, which is freely available at Software: RadVel (Fulton et al. 2018), RVSearch (Rosenthal et al. 2021), REBOUND (Rein & Liu 2012), SISTER (Hildebrandt et al. 2021).
Funding AgencyGrant Number
Subject Keywords:Exoplanets; Direct imaging; Radial velocity; Exoplanet systems; Exoplanet detection methods
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanets (498); Direct imaging (387); Radial velocity (1332); Exoplanet systems (484); Exoplanet detection methods (489)
Record Number:CaltechAUTHORS:20210610-100556900
Persistent URL:
Official Citation:Zhexing Li et al 2021 AJ 162 9
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109465
Deposited By: Tony Diaz
Deposited On:10 Jun 2021 17:15
Last Modified:10 Jun 2021 17:15

Repository Staff Only: item control page