The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system

Abstract

Context. Astrometric monitoring of directly-imaged exoplanets allows the study of their orbital parameters and system architectures. Because most directly-imaged planets have long orbital periods (>20 AU), accurate astrometry is challenging when based on data acquired on timescales of a few years and usually with different instruments. The LMIRCam camera on the LBT is being used for the LEECH survey to search for and characterize young and adolescent exoplanets in L' band, including their system architectures. Aims. We first aim to provide a good astrometric calibration of LMIRCam. Then, we derive new astrometry, test the predictions of the orbital model of 8:4:2:1 mean motion resonance proposed by Goździewski & Migaszewski, and perform new orbital fitting of the HR 8799 bcde planets. We also present deep limits on a putative fifth planet interior to the known planets. Methods. We use observations of HR 8799 and the Theta1 Ori C field obtained during the same run in October 2013. Results. We first characterize the distortion of LMIRCam. We determine a platescale and a true north orientation for the images of 10.707 +/- 0.012 mas/pix and -0.430 +/- 0.076 deg, respectively. The errors on the platescale and true north orientation translate into astrometric accuracies at a separation of 1 of 1.1 mas and 1.3 mas, respectively. The measurements for all planets are usually in agreement within 3 sigma with the ephemeris predicted by Goździewski & Migaszewski. The orbital fitting based on the new astrometric measurements favors an architecture for the planetary system based on 8:4:2:1 mean motion resonance. The detection limits allow us to exclude a fifth planet slightly brighter/more massive than HR 8799 b at the location of the 2:1 resonance with HR 8799 e (~9.5 AU) and about twice as bright as HR 8799 cde at the location of the 3:1 resonance with HR 8799 e (~7.5 AU).

10 pages, 3 figures, accepted for publication in A&A

References in corpus (15)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Optical Images of an Exosolar Planet 25 Light Years from Earth
• The Gemini Planet Imager: First Light
• On the Luminosity of Young Jupiters
• Fundamental limitations of high contrast imaging set by small sample statistics
• Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
• HST/NICMOS detection of HR 8799 b in 1998
• Reconnaissance of the HR 8799 Exosolar System II: Astrometry and Orbital Motion
• Astrometry and Photometry with Coronagraphs
• Gemini Planet Imager Spectroscopy of the HR 8799 planets c and d
• Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory
• Accurate Astrometry and Photometry of Saturated and Coronagraphic Point Spread Functions
• Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet
• Physical and orbital properties of Beta Pictoris b
• MOST light-curve analysis of the gamma Dor pulsator HR 8799, showing resonances and amplitude variations

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• Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
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• SPHERE dynamical and spectroscopic characterization of HD142527B
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• JWST-TST High Contrast: Living on the Wedge, or, NIRCam Bar Coronagraphy Reveals CO${}_2$ in the HR 8799 and 51 Eri Exoplanets' Atmospheres
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• Systematic Multi-Epoch Monitoring of LkCa 15: Dynamic Dust Structures on Solar-System Scales
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• The HOSTS survey: evidence for an extended dust disk and constraints on the presence of giant planets in the Habitable Zone of $\beta$ Leo
• The post-main-sequence fate of the HR 8799 planetary system
• ELT Imaging of MWC 297 from the 23-m LBTI: Complex Disk Structure and a Companion Candidate
• PACOME: Optimal multi-epoch combination of direct imaging observations for joint exoplanet detection and orbit estimation
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• Astrometric and photometric characterization of $\eta$ Tel B combining two decades of observations
• Precision Time-series Photometry in the Thermal Infrared with a 'Wall-Eyed' Pointing Mode at the Large Binocular Telescope
• The HOSTS Survey: Suspected variable dust emission and constraints on companions around θ Boo