Revisiting Proxima with ESPRESSO

Abstract

We aim to confirm the presence of Proxima b using independent measurements obtained with the new ESPRESSO spectrograph, and refine the planetary parameters taking advantage of its improved precision. We analysed 63 spectroscopic ESPRESSO observations of Proxima taken during 2019. We obtained radial velocity measurements with a typical radial velocity photon noise of 26 cm/s. We ran a joint MCMC analysis on the time series of the radial velocity and full-width half maximum of the cross-correlation function to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with stellar activity. We confirm the presence of Proxima b independently in the ESPRESSO data. The ESPRESSO data on its own shows Proxima b at a period of 11.218 $\pm$ 0.029 days, with a minimum mass of 1.29 $\pm$ 0.13 Me. In the combined dataset we measure a period of 11.18427 $\pm$ 0.00070 days with a minimum mass of 1.173 $\pm$ 0.086 Me. We find no evidence of stellar activity as a potential cause for the 11.2 days signal. We find some evidence for the presence of a second short-period signal, at 5.15 days with a semi-amplitude of merely 40 cm/s. If caused by a planetary companion, it would correspond to a minimum mass of 0.29 $\pm$ 0.08 Me. We find that the FWHM of the CCF can be used as a proxy for the brightness changes and that its gradient with time can be used to successfully detrend the radial velocity data from part of the influence of stellar activity. The activity-induced radial velocity signal in the ESPRESSO data shows a trend in amplitude towards redder wavelengths. Velocities measured using the red end of the spectrograph are less affected by activity, suggesting that the stellar activity is spot-dominated. The data collected excludes the presence of extra companions with masses above 0.6 Me at periods shorter than 50 days.

25 pages, 26 figures

References in corpus (48)

• emcee: The MCMC Hammer
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• Las Cumbres Observatory Global Telescope Network
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• No planet for HD 166435
• How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
• AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves (Expanded Edition)
• AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves
• The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample
• Stellar Diameters and Temperatures II. Main Sequence K & M Stars
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• A simple method to estimate radial velocity variations due to stellar activity using photometry
• Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
• Proxima's orbit around Alpha Centauri
• The HARPS search for southern extra-solar planets. X. A m sin i = 11 Mearth planet around the nearby spotted M dwarf GJ 674
• The habitability of Proxima Centauri b. I. Irradiation, rotation and volatile inventory from formation to the present
• Inferring probabilistic stellar rotation periods using Gaussian processes
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• Measuring precise radial velocities on individual spectral lines. I. Validation of the method and application to mitigate stellar activity
• A Kepler Study of Starspot Lifetimes with Respect to Light Curve Amplitude and Spectral Type
• The HARPS search for southern extra-solar planets XXXV. The interesting case of HD41248: stellar activity, no planets?
• Optical, UV, and X-Ray Evidence for a 7-Year Stellar Cycle in Proxima Centauri
• The First Naked-Eye Superflare Detected from Proxima Centauri
• Photometry of Proxima Centauri and Barnard's Star Using HST Fine Guidance Sensor 3: A Search for Periodic Variations
• Measuring precise radial velocities on individual spectral lines : II. Dependance of stellar activity signal on line depth
• Stacked Bayesian general Lomb-Scargle periodogram: Identifying stellar activity signals
• MOST Observations of our Nearest Neighbor: Flares on Proxima Centauri
• RUN DMC: An efficient, parallel code for analyzing Radial Velocity Observations using N-body Integrations and Differential Evolution Markov chain Monte Carlo
• On the use of marginal posteriors in marginal likelihood estimation via importance-sampling
• HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators
• Starspot distributions on fully convective M dwarfs: implications for radial velocity planet searches
• Activity-induced radial velocity jitter in a flaring M dwarf
• Flaring activity of Proxima Centauri from TESS observations: quasi-periodic oscillations during flare decay and inferences on the habitability of Proxima b
• HD 213885b: A transiting 1-day-period super-Earth with an Earth-like composition around a bright ($V=7.9$) star unveiled by TESS
• Catalog for the ESPRESSO blind radial velocity exoplanet survey
• Radial Velocities with CRIRES: Pushing precision down to 5-10 m/s
• A planetary system with gas giants and super-Earths around the nearby M dwarf GJ 676A. Optimizing data analysis techniques for the detection of multi-planetary systems
• HD2685 b: A Hot-Jupiter orbiting an early F-type star detected by TESS
• A Goldilocks principle for modeling radial velocity noise
• Double-Dipping: A New Relation between Stellar Rotation and Starspot Activity
• Decoding the radial velocity variations of HD41248 with ESPRESSO
• The Solar Neighborhood XXXI: Discovery of an Unusual Red+White Dwarf Binary at ~25 Parsecs via Astrometry and UV Imaging
• Proxima Centauri reloaded: Unravelling the stellar noise in radial velocities
• Flare activity and photospheric analysis of Proxima Centauri
• The RoPES project with HARPS and HARPS-N. I. A system of super-Earths orbiting the moderately active K-dwarf HD 176986

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• Diving into the planetary system of Proxima with NIRPS -- Breaking the metre per second barrier in the infrared
• MIRECLE: Science Yield for a Mid-IR Explorer-Class Mission to Study Non-Transiting Rocky Planets Orbiting the Nearest M-Stars Using Planetary Infrared Excess
• The need for a public forecast of stellar activity to optimise exoplanet radial velocity detections & transmission spectroscopy
• CaRM: Exploring the chromatic Rossiter-McLaughlin effect. The cases of HD 189733b and WASP-127b
• The Solar Neighborhood LI: A Variability Survey of Nearby M Dwarfs with Planets from Months to Decades with TESS and the CTIO/SMARTS 0.9 m Telescope
• Validation of a Third Planet in the LHS 1678 System
• Identifying Exoplanets with Deep Learning. IV. Removing Stellar Activity Signals from Radial Velocity Measurements Using Neural Networks
• SOAPv4: A new step toward modeling stellar signatures in exoplanet research
• Improved precision of radial velocity measurements after correction for telluric absorption
• Characterisation of magnetic activity of M dwarfs. Possible impact on the surface brightness
• ExoplANNET: A deep learning algorithm to detect and identify planetary signals in radial velocity data
• Two neighbours of the ultra-short-period Earth-sized planet K2-157 b in the warm Neptunian savanna
• Gl 725A b: a potential super-Earth detected with SOPHIE and SPIRou in an M dwarf binary system at 3.5 pc
• Detecting Atmospheric Molecules of Temperate Terrestrial Exoplanets using High-Resolution Spectroscopy in the Mid Infrared Domain
• Seeing-limited Coupling of Starlight into Single-mode Fiber with a Small Telescope
• HADES RV Programme with HARPS-N at TNG. XVI. A super-Earth in the habitable zone of the GJ 3998 multi-planet system
• Super-Earth masses and stellar abundances from NIRPS reveal tentative evidence for water-rich formation around M dwarfs
• L 363-38 b: a planet newly discovered with ESPRESSO orbiting a nearby M dwarf star
• The CARMENES search for exoplanets around M dwarfs : Understanding the wavelength dependence of radial velocity measurements
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