Radial Velocity Measurements of HR 8799 b and c with Medium Resolution Spectroscopy

Abstract

High-contrast medium resolution spectroscopy has been used to detect molecules such as water and carbon monoxide in the atmospheres of gas giant exoplanets. In this work, we show how it can be used to derive radial velocity (RV) measurements of directly imaged exoplanets. Improving upon the traditional cross-correlation technique, we develop a new likelihood based on joint forward modelling of the planetary signal and the starlight background (i.e., speckles). After marginalizing over the starlight model, we infer the barycentric RV of HR 8799 b and c in 2010 yielding -9.2 +- 0.5 km/s and -11.6 +- 0.5 km/s respectively. These RV measurements help to constrain the 3D orientation of the orbit of the planet by resolving the degeneracy in the longitude of ascending node. Assuming coplanar orbits for HR 8799 b and c, but not including d and e, we estimate Ω= 89 (+27,-17) deg and i = 20.8 (4.5,-3.7) deg.

Accepted to AJ

References in corpus (18)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Two accreting protoplanets around the young star PDS 70
• The fast spin-rotation of a young extrasolar planet
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• Pulkovo Compilation of Radial Velocities for 35495 Hipparcos Stars in a Common System
• Simultaneous Detection of Water, Methane and Carbon Monoxide in the Atmosphere of Exoplanet HR8799b
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• Cross-Correlation and Maximum Likelihood Analysis: A New Approach to Combine Cross-Correlation Functions
• Weighing The Non-Transiting Hot Jupiter Tau BOO b
• First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• Python Leap Second Management and Implementation of Precise Barycentric Correction (barycorrpy)
• Improving and Assessing Planet Sensitivity of the GPI Exoplanet Survey with a Forward Model Matched Filter
• Reconnaissance of the HR 8799 Exosolar System II: Astrometry and Orbital Motion
• The slow spin of the young sub-stellar companion GQ Lupi b and its orbital configuration
• Evidence against a strong thermal inversion in HD 209458 b from high-dispersion spectroscopy
• VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit

Cited by in corpus (52)

• orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community
• Detection and Bulk Properties of the HR 8799 Planets with High Resolution Spectroscopy
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• Deep exploration of the planets HR 8799 b, c, and d with moderate resolution spectroscopy
• A medium-resolution spectrum of the exoplanet HIP 65426 b
• Assessing the C/O Ratio Formation Diagnostic: A Potential Trend with Companion Mass
• Detecting exomoons from radial velocity measurements of self-luminous planets: application to observations of HR 7672 B and future prospects
• Four-of-a-kind? Comprehensive atmospheric characterisation of the HR 8799 planets with VLTI/GRAVITY
• A detailed characterization of HR 8799's debris disk with ALMA in Band 7
• Peering into the Young Planetary System AB Pic. Atmosphere, Orbit, Obliquity & Second Planetary Candidate
• On the Chemical Abundance of HR 8799 and the Planet c
• The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES${}^{+}$
• Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multi-epoch Vortex Coronagraphy Upper Limits
• Molecular mapping of the PDS70 system: No molecular absorption signatures from the forming planet PDS70 b
• Direct emission spectroscopy of exoplanets with the medium resolution imaging spectrometer on board JWST MIRI: I. Molecular mapping and sensitivity to instrumental effects
• The ESO SupJup Survey III: Confirmation of 13CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES+
• A High-Contrast Search for Variability in HR 8799bc with VLT-SPHERE
• The Orbital Eccentricities of Directly Imaged Companions Using Observable-Based Priors: Implications for Population-level Distributions
• Dynamical Mass of the Exoplanet Host Star HR 8799
• The ESO SupJup Survey II: The 12C/13C ratios of three young brown dwarfs with CRIRES${}^{+}$
• Behind the Mask: can HARMONI@ELT detect biosignatures in the reflected light of Proxima b?
• JWST-TST High Contrast: Living on the Wedge, or, NIRCam Bar Coronagraphy Reveals CO${}_2$ in the HR 8799 and 51 Eri Exoplanets' Atmospheres
• Simulated performance of the molecular mapping for young giant exoplanets with the Medium Resolution Spectrometer of JWST/MIRI
• Biases in orbit fitting of directly-imaged exoplanets with small orbital coverage
• Deep orbital search for additional planets in the HR 8799 system
• Rotation and Abundances of the Benchmark Brown Dwarf HD 33632 Ab from Keck/KPIC High-resolution Spectroscopy
• Diffraction-limited integral-field spectroscopy for extreme adaptive optics systems with the Multi-Core fiber-fed Integral-Field Unit
• Fresh view of the hot brown dwarf HD 984 B through high-resolution spectroscopy
• Detectability of satellites around directly imaged exoplanets and brown dwarfs
• Atmospheric characterization of the super-Jupiter HIP 99770 b with KPIC
• Measuring the variability of directly imaged exoplanets using vector Apodizing Phase Plates combined with ground-based differential spectrophotometry
• The ESO SupJup Survey VII: Clouds and line asymmetries in CRIRES${}^{+}$ J-band spectra of the Luhman 16 binary
• Detecting Exoplanets Closer to Stars with Moderate Spectral Resolution Integral-Field Spectroscopy
• Jupiter-like uniform metal enrichment in a system of multiple giant exoplanets
• Trade-offs in high-contrast integral field spectroscopy for exoplanet detection and characterisation: Young gas giants in emission
• Machine Learning for Exoplanet Detection in High-Contrast Spectroscopy: Revealing Exoplanets by Leveraging Hidden Molecular Signatures in Cross-Correlated Spectra with Convolutional Neural Networks
• Multi-modal atmospheric characterization of $\beta$ Pictoris b: Adding high-resolution continuum spectra from GRAVITY
• Impacts of high-contrast image processing on atmospheric retrievals
• Exoplanets detection limits using spectral cross-correlation with spectro-imaging. An analytical model applied to the case of ELT-HARMONI
• Spectral unmixing for exoplanet direct detection in hyperspectral data
• Instrumentation prospects for rocky exoplanet atmospheres studies with high resolution spectroscopy
• Direct Spectroscopy of 51 Eridani b with JWST NIRSpec
• The ESO SupJup Survey VIII. Chemical fingerprints of young L dwarf twins
• CROCODILE \\ Incorporating medium-resolution spectroscopy of close-in directly imaged exoplanets into atmospheric retrievals via cross-correlation
• Integral field spectroscopy with the solar gravitational lens
• Velocity offset between emission and absorption lines might be an effective indicator of dual core system
• High-contrast spectroscopy with the new VLT/ERIS instrument: Molecular maps and radial velocity of the gas giant AF Lep b
• Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions
• Exoplanets in reflected starlight with dual-field interferometry: A case for shorter wavelengths and a fifth Unit Telescope at VLTI/Paranal
• Combining high-contrast imaging with high-resolution spectroscopy: Actual on-sky MIRI/MRS results compared to expectations
• Machine learning for exoplanet detection in high-contrast spectroscopy Combining cross correlation maps and deep learning on medium-resolution integral-field spectra
• Panchromatic View of the Frigid Jovian Exoplanet COCONUTS-2 b