Jean-Philippe Beaulieu

Directeur de recherche CNRS
Honorary Reader at the University College of London

Planning for the coming months: 

  • Currently confined in France

Curiculum vitae

Publications (2008-2013)

Latest publication, at the invitation of Julien Flak, Poésie Féroce, arts anciens de Nouvelle Irelande.

A book published, "Secret Garden at Recherche Bay - 1792". Launched in Hobart on February 24 2016.

 

PLANET collaboration

ECHO space mission

EUCLID space mission

Oceanic art, New Ireland, Uli, Malagan

Trip to Tierra de Fuego


Fun :

Hotel Mauna Kea (the truth about observing)

La Silla under the snow (2004)

The PLANET collaboration was involved in the monitoring of the Comet 9P Tempel-1 before the Deep Impact planned on July 4, 2005. Check the gallery of pictures of the comet and  the comet update from July 5, 11h00

The french garden of Recherche Bay (a kitchen garden from d'Entrecasteaux expedition unearthed in 2003 in Tasmania)

Daniel estrade, etchings, watercolor

Isle of skye, sea eagle

List of usefull sites


A 5.5 Earth mass planet detected by microlensing, Beaulieu et al. 2006, Nature. Download the article here. Artistic view of the planet 


HOLMES : 2007-2011

Hunting cOol Low Mass Extrasolar planetS 2007-2011

Our primary objective is the discovery of low mass planets (1 – 15 Earth masses) within 1 – 5 AU of the most common stars in our Galaxy by microlensing effects in order to measure their frequency. As a secondary objective we will do detailed studies of known planetary systems (including probing their atmospheres during planetary transits) and estimate their physical properties.

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My research activities have been fully dedicated to the field of exoplanet searches and characterization over the last 23 years. I am activily working on three topics simultaneously :

- Demographics of planets close to their birth place & their occurrence in the disk and the bar of our Galaxy. COLD-WORLDS

- Characterisation of extrasolar planets atmosphere with ARIEL space mission

- An exoplanet census via microlensing with EUCLID, WFIRST

ARIEL (a 1m space telescope concept to do spectroscopy of extrasolar planets in the range 0.5-9 microns) due to launch in 2028. EUCLID is an accepted ESA mission (wide field imager in space) due to be launched on 2022.

 

COLD-WORLDS 2018-2022

COLD-WORLDS aims to use gravitational microlensing to explore a unique niche, cold planets down to Earth mass orbiting around any kind of star, at any distance towards the Galactic center, rogue planets and moons orbiting exoplanets (exomoons). These are in very different environments from most known exoplanets, allowing key tests of planet formation theory. Indeed, the maximum sensitivity is for planets at the snow line, close their formation location. To date, 55 microlensing planets have been published and these results challenge theories of planet formation. The core accretion population synthesis predictions by Ida’s and Bern’s groups are quite similar and both under-predict the number of observed cold planets at a mass ratio of q =2E-4) by a factor of ~25. It might be due to the run-away gas accretion phase of planet formation, which is a basic feature of the core accretion theory. Alternatively, it could be that there is some host star mass dependence of this run-away gas accretion gap that smooths out this feature when plotted as a function of mass ratio. So, it is important to accurately determine the individual masses for the planets and host stars.

Microlensing provides precise mass-ratio and projected separations in units of the Einstein ring radius. In order to obtain the physical parameters (mass, distance, orbital separation) of the system, it is necessary to combine the result of light curve modeling with lens mass-distance relations and/or perform a Bayesian analysis with a galactic model. Often, physical parameters are determined to 30-50 %, or even worse. However, we have shown that a tight constraint can be obtained on the lens mass-distance, thanks to detection or upper limits on its luminosity using high angular resolution observations with 8m class telescopes or HST. The pioneering work by our team shows that we can derive physical parameters on known systems to 10 % or better with Keck adaptive optics for instance. In the uncertainty budget, we would then be dominated by extinction correction, distance to the source, calibrating luminosity function of main sequence stars and our understanding of the galactic structure.
COLD-WORLDS will use infrared wide field imagers (public surveys from VISTA, UKIRT, and dedicated observations) and operate adaptive optics on 10m class telescopes. We obtained data already on 30 systems (Keck, VLT, SUBARU, HST) and we have 10 nights approved as Key Strategic Mission Support to WFIRST with Keck for the years 2018-2019. By 2019, we will have observations of the host stars of ~100+ systems with cold planets. We will use Gaia DR2 to measure the source distances, revisit the galactic disk, bar, bulge. Combining Gaia with the multiband observations, we will revisit our model of extinction. It will also give the kinematics on the line of sights to the Bulge and will allow to revise our Bayesian modeling of microlensing plane.
We will then perform demographics of the Disk and Bulge cold planet populations and address the following science objectives.

1/ What is the mass distribution of cold planets down to ~1 Earth mass at the snow line, where most planets are formed?
2/ What is the spatial distribution and abundance of cold planets towards the centre of our Galaxy?
3/ How to routinely achieve better than 10% accuracy in microlensing planet mass determinations with the next generation of satellites (Euclid and WFIRST)?
4/ Producing a near-infrared (JHK) photometric archive from ESO dedicated surveys of the Galactic bulge, a lasting resource for broad areas of stellar and galactic astronomy.
Our highly dedicated team covers all the range of needed expertise. It is also using public data and has all the needed allocated telescope time. It is a risk free, high impact project, giving roots to the Euclid and WFIRST microlensing surveys, while providing important results and useful legacy products.

 

 

 

Older press release :

Press release KECK-II and Hubble Space Telescope (July 30 2016),

KECK-II & Hubble Space telescope team up to confirm distant Uranus mass planet through microlensing.


Selected publications :

Beaulieu, J.-P. et al., 2006, Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing, Nature 439, 437–440

Tinetti, G., Vidal-Madjar, A., Liang, M.-C., Beaulieu, J.P. et al. 2007, Water vapour in the atmosphere of a transiting extrasolar planet, Nature, 448(7150), 169–171.

Gaudi, B.S. et al., 2008, Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing, Science 319, 927–930.

Cassan A. Kubas D., Beaulieu J.P., et al., 2012, One or more bound planets per Milky Way star from microlensing observations, Nature 481, 167-169.EUCLID is an accepted ESA mission (wide field imager in space) due to be launched on 2020. ECHO (a 1.3m space telescope concept to do spectroscopy of extrasolar planets in the range 0.5-16 microns). It will be re-submitted to ESA this fall.