Upper limits for Mass and Radius of objects around Proxima Cen from SPHERE/VLT

Abstract

The recent discovery of an earth-like planet around Proxima Centauri has drawn much attention to this star and its environment. We performed a series of observations of Proxima Centauri using SPHERE, the planet finder instrument installed at the ESO Very Large Telescope UT3, using its near infrared modules, IRDIS and IFS. No planet was directly detected but we set upper limits on the mass up to 7 au exploiting the AMES-COND models. Our IFS observations reveal that no planet more massive than ~6-7 M Jup can be present within 1 au. The dual band imaging camera IRDIS also enables us to probe larger separations than the other techniques like the radial velocity or astrometry. We obtained mass limits of the order of 4 M Jup at separations of 2 au or larger representing the most stringent mass limits at separations larger than 5 au available at the moment. We also did an attempt to estimate the radius of possible planets around Proxima using the reflected light. Since the residual noise for this observations are dominated by photon noise and thermal background, longer exposures in good observing conditions could further improve the achievable contrast limit.

arXiv comment5 pages, 4 figures, accepted by MNRAS

References in corpus (17)

• Validation of the new Hipparcos reduction
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• Fundamental limitations of high contrast imaging set by small sample statistics
• Photometric characterization of exoplanets using angular and spectral differential imaging
• First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR8799 exoplanetary system
• Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
• The M dwarf planet search programme at the ESO VLT + UVES. A search for terrestrial planets in the habitable zone of M dwarfs
• Asteroseismology and calibration of alpha Cen binary system
• High-contrast imaging of Sirius~A with VLT/SPHERE: Looking for giant planets down to one astronomical unit
• Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory
• Precision radial velocities of 15 M5 - M9 dwarfs
• On the uncertain nature of the core of $\mathbf{\alpha }$ Cen A
• The Solar Neighborhood. XXXIV. A Search for Planets Orbiting Nearby M Dwarfs using Astrometry
• MESS (Multi-purpose Exoplanet Simulation System): A Monte Carlo tool for the statistical analysis and prediction of exoplanets search results
• Toward detection of terrestrial planets in the habitable zone of our closest neighbor: Proxima Centauri
• Microlensing Events by Proxima Centauri in 2014 and 2016: Opportunities for Mass Determination and Possible Planet Detection

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• Atmospheric characterization of directly imaged exoplanets with JWST/MIRI
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