I’m still writing a few more words about my research, come back in a few days.
What I do for a living
I search for exoplanets. Planets around other stars.
The ultimate goal is to find a planet like the Earth orbiting a star like the Sun.
But that’s not so easy.
Low-mass planets (like the Earth, with a mere 6 septillion kg)
impact tiny effects on their host stars,
in particular changing their radial velocity (RV) or their brightness.
This is the basis of the RV
(not that)
and transit (not that) methods for planet detection.

The whole problem boils down to finding periodic signals of very low amplitude in radial velocity time series which can cover decades.
…
During my PhD, I was in charge of a radial-velocity survey of metal-poor stars, with the goal of estimating the occurrence rate of low-mass planets in the low metallicity regime. I found a planet occurrence rate smaller than that of solar-metallicity stars, which means that the famous giant planet – metallicity correlation also extends to the population of low-mass planets.
Software
I enjoy writing code and developing software for science.
Most of my projects can be found on Github.
Here are some important ones:
bgls - Bayesian version of the Generalized Lomb-Scargle periodogram
iCCF - Line profile / asymmetry indicators
keplerian - the Keplerian function
kima - Exoplanet detection in RVs with DNest4 and GPs
SAM - Hi, I’m SAM
Over at the blog, I’ve talked about a number of other small codes.
Publications
I am co-author of 71 refereed research papers. Here is a complete list:
- Improving circumbinary planet detections by fitting their binary's apsidal precession
Monthly Notices of the Royal Astronomical Society, vol. 521, issue 2, pp. 1871, 2023 - Modelling stellar activity with Gaussian process regression networks
Monthly Notices of the Royal Astronomical Society, vol. 519, issue 4, pp. 5439, 2023 - Two temperate Earth-mass planets orbiting the nearby star GJ 1002
Astronomy and Astrophysics, vol. 670, A5, 2023 - KOBEsim: A Bayesian observing strategy algorithm for planet detection in radial velocity blind-search surveys
Astronomy and Astrophysics, vol. 669, A18, 2023 - The KOBE experiment: K-dwarfs Orbited By habitable Exoplanets. Project goals, target selection, and stellar characterization
Astronomy and Astrophysics, vol. 667, A102, 2022 - Automatic model-based telluric correction for the ESPRESSO data reduction software. Model description and application to radial velocity computation
Astronomy and Astrophysics, vol. 666, A196, 2022 - HD 23472: a multi-planetary system with three super-Earths and two potential super-Mercuries
Astronomy and Astrophysics, vol. 665, A154, 2022 - A novel framework for semi-Bayesian radial velocities through template matching
Astronomy and Astrophysics, vol. 663, A143, 2022 - The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities
The Astronomical Journal, vol. 163, issue 4, pp. 171, 2022 - BEBOP III. Observations and an independent mass measurement of Kepler-16 (AB) b - the first circumbinary planet detected with radial velocities
Monthly Notices of the Royal Astronomical Society, vol. 511, issue 3, pp. 3561, 2022 - BEBOP II: sensitivity to sub-Saturn circumbinary planets using radial-velocities
Monthly Notices of the Royal Astronomical Society, vol. 511, issue 3, pp. 3571, 2022 - A candidate short-period sub-Earth orbiting Proxima Centauri
Astronomy and Astrophysics, vol. 658, A115, 2022 - Composition of super-Earths, super-Mercuries, and their host stars
Communications of the Byurakan Astrophysical Observatory, vol. 68, issue 2, pp. 447, 2021 - A compositional link between rocky exoplanets and their host stars
Science, vol. 374, issue 6565, pp. 330, 2021 - HD 22496 b: The first ESPRESSO stand-alone planet discovery
Astronomy and Astrophysics, vol. 654, A60, 2021 - Warm terrestrial planet with half the mass of Venus transiting a nearby star
Astronomy and Astrophysics, vol. 653, A41, 2021 - The SOPHIE search for northern extrasolar planets. XVIII. Six new cold Jupiters, including one of the most eccentric exoplanet orbits
Astronomy and Astrophysics, vol. 653, A78, 2021 - Scheduling strategies for the ESPRESSO follow-up of TESS targets
Monthly Notices of the Royal Astronomical Society, vol. 503, issue 4, pp. 5504, 2021 - Stellar clustering and orbital architecture of planetary systems
Astronomy and Astrophysics, vol. 649, A111, 2021 - ESPRESSO high-resolution transmission spectroscopy of WASP-76 b
Astronomy and Astrophysics, vol. 646, A158, 2021 - ESPRESSO at VLT. On-sky performance and first results
Astronomy and Astrophysics, vol. 645, A96, 2021 - Broadband transmission spectroscopy of HD 209458b with ESPRESSO: evidence for Na, TiO, or both
Astronomy and Astrophysics, vol. 644, A51, 2020 - Planetary system LHS 1140 revisited with ESPRESSO and TESS
Astronomy and Astrophysics, vol. 642, A121, 2020 - A precise architecture characterization of the π Mensae planetary system
Astronomy and Astrophysics, vol. 642, A31, 2020 - Benchmark stars, benchmark spectrographs. Detailed spectroscopic comparison of ESPRESSO, PEPSI, and HARPS data for Gaia benchmark stars
Astronomy and Astrophysics, vol. 642, A182, 2020 - Detection and Characterization Methods of Exoplanets
Oxford Research Encyclopedia of Planetary Science, vol. None, 189, 2020 - Revisiting Proxima with ESPRESSO
Astronomy and Astrophysics, vol. 639, A77, 2020 - The correlation between photometric variability and radial velocity jitter. Based on TESS and HARPS observations
Astronomy and Astrophysics, vol. 639, A35, 2020 - Can we detect the stellar differential rotation of WASP-7 through the Rossiter-McLaughlin observations?
Monthly Notices of the Royal Astronomical Society, vol. 493, issue 4, pp. 5928, 2020 - Decoding the radial velocity variations of HD 41248 with ESPRESSO
Astronomy and Astrophysics, vol. 635, A13, 2020 - Can planetary rings explain the extremely low density of HIP 41378 f?
Astronomy and Astrophysics, vol. 635, L8, 2020 - Quantifying the Bayesian Evidence for a Planet in Radial Velocity Data
The Astronomical Journal, vol. 159, issue 2, pp. 73, 2020 - Improving transit characterisation with Gaussian process modelling of stellar variability
Astronomy and Astrophysics, vol. 634, A75, 2020 - Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPS
Astronomy and Astrophysics, vol. 631, A90, 2019 - Gaussian process modelling of granulation and oscillations in red giant stars
Monthly Notices of the Royal Astronomical Society, vol. 489, issue 4, pp. 5764, 2019 - Beyond the exoplanet mass-radius relation
Astronomy and Astrophysics, vol. 630, A135, 2019 - The metallicity-period-mass diagram of low-mass exoplanets
Monthly Notices of the Royal Astronomical Society, vol. 485, issue 3, pp. 3981, 2019 - The GAPS Programme with HARPS-N at TNG. XVIII. Two new giant planets around the metal-poor stars HD 220197 and HD 233832
Astronomy and Astrophysics, vol. 621, A110, 2019 - SWEET-Cat updated. New homogenous spectroscopic parameters
Astronomy and Astrophysics, vol. 620, A58, 2018 - ACTIN: A tool to calculate stellar activity indices
The Journal of Open Source Software, vol. 3, issue 31, pp. 667, 2018 - Planets around evolved intermediate-mass stars. II. Are there really planets around IC 4651 No. 9122, NGC 2423 No. 3, and NGC 4349 No. 127?
Astronomy and Astrophysics, vol. 619, A2, 2018 - Activity induced variation in spin-orbit angles as derived from Rossiter-McLaughlin measurements
Astronomy and Astrophysics, vol. 619, A150, 2018 - The TROY project. II. Multi-technique constraints on exotrojans in nine planetary systems
Astronomy and Astrophysics, vol. 618, A42, 2018 - Chemical Abundances of Neutron-capture Elements in Exoplanet-hosting Stars
Publications of the Astronomical Society of the Pacific, vol. 130, issue 991, pp. 094202, 2018 - Recovering the colour-dependent albedo of exoplanets with high-resolution spectroscopy: from ESPRESSO to the ELT
Monthly Notices of the Royal Astronomical Society, vol. 478, issue 4, pp. 5240, 2018 - kima: Exoplanet detection in radial velocities
The Journal of Open Source Software, vol. 3, issue 26, pp. 487, 2018 - An Earth-sized exoplanet with a Mercury-like composition
Nature Astronomy, vol. 2, 393, 2018 - Distinguishing the albedo of exoplanets from stellar activity
Astronomy and Astrophysics, vol. 611, A8, 2018 - The TROY project: Searching for co-orbital bodies to known planets. I. Project goals and first results from archival radial velocity
Astronomy and Astrophysics, vol. 609, A96, 2018 - Tutorial: Detecting Planetary Transits and Radial-Velocity Signals
Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds, vol. 49, 267, 2018 - Exoplanetary Science: An Overview
Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds, vol. 49, 165, 2018 - Constraining planet structure and composition from stellar chemistry: trends in different stellar populations
Astronomy and Astrophysics, vol. 608, A94, 2017 - Precise masses for the transiting planetary system HD 106315 with HARPS
Astronomy and Astrophysics, vol. 608, A25, 2017 - Understanding stellar activity-induced radial velocity jitter using simultaneous K2 photometry and HARPS RV measurements
Astronomy and Astrophysics, vol. 606, A107, 2017 - Observational evidence for two distinct giant planet populations
Astronomy and Astrophysics, vol. 603, A30, 2017 - A Pragmatic Bayesian Perspective on Correlation Analysis. The exoplanetary gravity - stellar activity case
Origins of Life and Evolution of the Biosphere, vol. 46, issue 4, pp. 385, 2016 - Abundance trend with condensation temperature for stars with different Galactic birth places
Astronomy and Astrophysics, vol. 592, A87, 2016 - Is the activity level of HD 80606 influenced by its eccentric planet?
Astronomy and Astrophysics, vol. 592, A143, 2016 - An extreme planetary system around HD 219828. One long-period super Jupiter to a hot-Neptune host star
Astronomy and Astrophysics, vol. 592, A13, 2016 - ζ2 Reticuli, its debris disk, and its lonely stellar companion ζ1 Ret. Different Tc trends for different spectra
Astronomy and Astrophysics, vol. 591, A34, 2016 - The HARPS search for southern extra-solar planets. XL. Searching for Neptunes around metal-poor stars
Astronomy and Astrophysics, vol. 589, A25, 2016 - Uncovering the planets and stellar activity of CoRoT-7 using only radial velocities
Astronomy and Astrophysics, vol. 588, A31, 2016 - The HARPS search for southern extra-solar planets. XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune
Astronomy and Astrophysics, vol. 585, A135, 2016 - Identifying the best iron-peak and α-capture elements for chemical tagging: The impact of the number of lines on measured scatter
Astronomy and Astrophysics, vol. 583, A94, 2015 - Evidence for a spectroscopic direct detection of reflected light from
51 Pegasi b
Astronomy and Astrophysics, vol. 576, A134, 2015 - BGLS: A Bayesian formalism for the generalised Lomb-Scargle periodogram
Astronomy and Astrophysics, vol. 573, A101, 2015 - Exoplanet hosts reveal lithium depletion. Results from a homogeneous statistical analysis
Astronomy and Astrophysics, vol. 570, A21, 2014 - Asteroseismic Estimate of Helium Abundance of a Solar Analog Binary System
The Astrophysical Journal, vol. 790, issue 2, pp. 138, 2014 - The HARPS search for southern extra-solar planets. XXXV. The interesting case of HD 41248: stellar activity, no planets?
Astronomy and Astrophysics, vol. 566, A35, 2014 - On the possibility of using seismic probes to study the core composition in pulsating white dwarfs
Astronomische Nachrichten, vol. 333, issue 10, pp. 954, 2012