The Extreme Precision Radial Velocity Research Coordination Network (EPRV RCN) will host an on-line workshop focused on the synergies between EPRV and solar physics on Wednesday, June 10th & Thursday, 11th from 3:00 - 5:30p UTC / 8:00 - 10:30a Pacific US time each day. The goal of this workshop is to explore potential synergies amongst data/facilities/analysis methods between EPRV solar facilities and the solar physics community. Ideally this will raise awareness of the resources developed by each community that may be of assistance to the other and potentially spark new collaboration ideas!

Workshop Agenda

Additional workshop context:
The Extreme Precision Radial Velocity (EPRV) community aims to robustly detect temperate, Earth-mass planets orbiting nearby Sun-like stars via Doppler shift signatures in high resolution, visible spectra. For context, the RV signal of the Earth around the Sun is only 9 cm/s, while the variability introduced by (primarily) magnetic phenomena on the Sun are 1-5 m/s even during low activity spans. The largest amplitude effects arise from spots and faculae, alongside their modulation over the magnetic cycles, but oscillations, granulation, and super-granulation remain a challenge for our community as well; supergranulation in particular may present one of the most fundamental barriers to exoplanet detection due to its longer timescale and poorly understood origin (see figure below and the recent Precise Radial Velocities Annual Reviews article for further comparison between relevant signals). We are working to disentangle these phenomena from the wholesale Doppler reflex motion induced by planetary companions by identifying their signatures in the spectra across the visible domain used for exoplanet hunting.

Within the RV field, small diameter, solar-telescopes that feed our high resolution (R~100K), visible (~400-900nm) spectrographs have collected years of stabilized, high cadence, high SNR, disk- integrated spectra of the sun (see, e.g., Dumusque et al. 2026). We are using these to disentangle line deformations described above from true Doppler shifts, sometimes via comparisons to solar data from (e.g.,) the Solar Dynamics Observatory and sometimes via RV-only analyses.

Summary of the approximate timescales and RV semi-amplitudes of the stellar phenomena that most directly impact EPRV science efforts for a Sun-like star, with the RV semi-amplitudes of Earth, Jupiter, and 51 Peg b for reference. These phenomena span timescales from minutes to decades and RV semi-amplitudes of cm/s to dozens of m/s which poses significant challenges for designing RV survey and analysis techniques that can accurately sample, model, and mitigate their impacts. The background grayscale image represents the solar power spectrum density from Al Moulla et al. (2023) with fitted contributions for the different stellar phenomena as colored dashed lines. Figure 9 from Burt et al. 2026, adapted from Al Moulla et al. (2023) and a figure concept from Ryan Rubenzahl.