25 citations · 44 across the 9 of their papers we have counts for
10 papers
Saturns Are Not Large Neptunes: The effect of removing inflated giants from empirical mass-radius relations
Georgina Dransfield, Valentina Tardugno, Niamh K. O'Sullivan
Empirical mass-radius relations have long been used in exoplanetology to study planet demographics and to predict masses and radii for objects where only one of these is known. Inf…
The Fe I 4377 Å Line as a Solar Faculae Indicator: Insights from Spectral Ratio Analysis
Katlyn L. Hobbs, Christopher A. Watson, Jean C. Costes +21
Faculae are a dominant source of stellar activity noise in radial velocity measurements, yet their low contrast and broad surface distribution make them difficult to track in disc-…
A Decade of Solar High-Fidelity Spectroscopy and Precise Radial Velocities from HARPS-N
X. Dumusque, K. Al Moulla, M. Cretignier +53
We recently released 10 years of HARPS-N solar telescope and the goal of this manuscript is to present the different optimisations made to the data reduction, to describe data cura…
Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars
Baptiste Klein, Suzanne Aigrain, Michael Cretignier +9
Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we…
Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle
Niamh K. O'Sullivan, Suzanne Aigrain, Michael Cretignier +9
In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-s…
Investigating stellar activity through eight years of Sun-as-a-star observations
Baptiste Klein, Suzanne Aigrain, Michael Cretignier +11
Stellar magnetic activity induces both distortions and Doppler-shifts in the absorption line profiles of Sun-like stars. Those effects produce apparent radial velocity (RV) signals…
Modelling stochastic and quasi-periodic behaviour in stellar time-series: Gaussian process regression versus power-spectrum fitting
Niamh K. O'Sullivan, Suzanne Aigrain
As the hunt for an Earth-like exoplanets has intensified in recent years, so has the effort to characterise and model the stellar signals that can hide or mimic small planetary sig…
TOI-837b is a Young Saturn-sized Exoplanet with a Massive 70 Core
Oscar Barragán, Haochuan Yu, Alix Violet Freckelton +10
We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837b, with an orbital period of 8.32d. Ut…
Modelling stellar variability in archival HARPS data: I -- Rotation and activity properties with multi-dimensional Gaussian Processes
Haochuan Yu, Suzanne Aigrain, Baptiste Klein +4
Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-meter per second accuracy, the detection of low-mass planets is still very challengi…
Revisiting K2-233 spectroscopic time-series with multidimensional Gaussian Processes
Oscar Barragán, Edward Gillen, Suzanne Aigrain +7
Detecting planetary signatures in radial velocity time-series of young stars is challenging due to their inherently strong stellar activity. However, it is possible to learn inform…