Measuring masses of transiting Earth-like planets: first insights from the PLATO RV data challenge
Abstract
The PLATO Stellar Variability Mitigation Working Group designed a radial-velocity (RV) data challenge to assess the precision and accuracy achievable on RV semi-amplitudes in the context of the future PLATO follow-up. Using Sun-as-a-star observations obtained with HARPS-N, we generated three multi-planet systems with realistic sampling, an effective signal-to-noise ratio of S/N ~ 450, an exposure time of 15 minutes, and a total of approximately 1000 observations. The resulting data set is publicly available and can serve as a benchmark for the community to test and compare RV analysis methods. Eight independent teams participated in the challenge, aiming to recover the semi-amplitudes of both transiting and non-transiting planets. A meta-analysis of the submitted results shows that, with current data analysis methods, HARPS-N-like stability and the observing strategy studied in this paper, achieving a precision on semi-amplitudes better than 10% for habitable-zone signals around a solar-type star is challenging, and is typically limited to planets with masses of approximately 8-10 Earth masses. This performance is expected to improve for K dwarfs, where planets down to approximately 2-5 Earth masses may be characterized at a similar level of precision. Finally, based on the results of this challenge and the occurrence of false positives, we derive an empirical detection threshold for RV surveys, which can be used to distinguish robust planetary detections from candidates.
Versions
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BibTeX
@misc{cretignier2026measuring,
title = {{Measuring masses of transiting Earth-like planets: first insights from the PLATO RV data challenge}},
author = {M. Cretignier and N. C. Hara and S. Aigrain and S. Sulis and F. Bouchy and S. T. Hodgkin and J. Blanco-Pozo and A. Collier-Cameron and M. Damasso and E. C. Gonçalves and L. Malavolta and G. Mantovan and D. Nardiello and M. Perger and I. Ribas and Y. Zhao and X. Dumusque and A. Mortier and K. Al Moulla and S. C. C. Barros and A. Santerne and N. C. Santos and C. San Nicolas Martinez and C. Watson and T. Wilson and S. Udry and for the PLATO Stellar Variability Working Group},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.36201},
eprint = {2610.36201},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.36201},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Measuring masses of transiting Earth-like planets: first insights from the PLATO RV data challenge
AU - M. Cretignier
AU - N. C. Hara
AU - S. Aigrain
AU - S. Sulis
AU - F. Bouchy
AU - S. T. Hodgkin
AU - J. Blanco-Pozo
AU - A. Collier-Cameron
AU - M. Damasso
AU - E. C. Gonçalves
AU - L. Malavolta
AU - G. Mantovan
AU - D. Nardiello
AU - M. Perger
AU - I. Ribas
AU - Y. Zhao
AU - X. Dumusque
AU - A. Mortier
AU - K. Al Moulla
AU - S. C. C. Barros
AU - A. Santerne
AU - N. C. Santos
AU - C. San Nicolas Martinez
AU - C. Watson
AU - T. Wilson
AU - S. Udry
AU - for the PLATO Stellar Variability Working Group
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.36201
UR - https://arxiv.org/abs/2610.36201
AB - The PLATO Stellar Variability Mitigation Working Group designed a radial-velocity (RV) data challenge to assess the precision and accuracy achievable on RV semi-amplitudes in the context of the future PLATO follow-up. Using Sun-as-a-star observations obtained with HARPS-N, we generated three multi-planet systems with realistic sampling, an effective signal-to-noise ratio of S/N ~ 450, an exposure time of 15 minutes, and a total of approximately 1000 observations. The resulting data set is publicly available and can serve as a benchmark for the community to test and compare RV analysis methods. Eight independent teams participated in the challenge, aiming to recover the semi-amplitudes of both transiting and non-transiting planets. A meta-analysis of the submitted results shows that, with current data analysis methods, HARPS-N-like stability and the observing strategy studied in this paper, achieving a precision on semi-amplitudes better than 10% for habitable-zone signals around a solar-type star is challenging, and is typically limited to planets with masses of approximately 8-10 Earth masses. This performance is expected to improve for K dwarfs, where planets down to approximately 2-5 Earth masses may be characterized at a similar level of precision. Finally, based on the results of this challenge and the occurrence of false positives, we derive an empirical detection threshold for RV surveys, which can be used to distinguish robust planetary detections from candidates.
ER -