S P E C T R A L    F I D E L I T Y

4 - 8 September 2023

Florence, Italy


Conference venue: Istituto degli Innocenti - Piazza SS Annunziata, Firenze


A joint-conference organised by ESO, INAF-Osservatorio Astrofisico di Arcetri and UniGE


Spectroscopy is the main tool to peer into the physics of the Universe. Precise and accurate spectroscopy is going to produce some of the most spectacular results in the coming years, from Big Bang Nucleosynthesis, the chemistry of stars and interstellar medium, the measurement of the acceleration of the Universe, the variability of physical constants, the age of the Universe and the nature of gravitation, the detection of terrestrial exo-planets and the analysis of their atmospheres. Yet, spectroscopic observations, data reduction, and analysis methods still suffer from shortcomings and limitations. With the installation of HARPS, 20 years ago, at the 3.6m telescope, in La Silla, ESO community has gained a central role in this research. HARPS has been  transformational, paving the way to the new generations of planet hunters.

Innovative ideas are being developed to use these instrumental capabilities beyond the exoplanet search, and this research  is rapidly expanding to the IR domain. In addition to Doppler shifts precision and accuracy, other aspects of spectral fidelity include: how well are the spectra characterized for noise, scattered light, detector effects, instrumental profile? And, when moving to abundances, what are abundance realistic uncertainties? Is precision enough or is accuracy required? Which are the limits of precise and accurate spectroscopy and which exciting science will new performances enable? Which science require spectral fidelity and how can we enable it? What is its present status and future perspective?

The aim of the conference is to discuss all the above topics, some of which were addressed in an ESO/Lisbon/Aveiro conference in 2006 (“Precision Spectroscopy”). It seems very timely to address them again after 17 years, with a view to the long heritage of HARPS, the first 5 years of operations of ESPRESSO, the new results from NIR spectrographs, ANDES and the ELTs.

Starting from these simple questions, a number of  topics were identified:


- Stellar Abundances

- Data Reduction


- Stellar physics

- Data Analysis


- Exoplanets & atmospheres

- Ancillary developments (simulations, models, laboratory, etc.) 


- Fundamental Physics



- ISM &  IGM

- High spectral fidelity @ ELTs


- Cosmology

- Massive Surveys and Fidelity


- Instrumental requirements for Fidelity 

- Legacy of spectral fidelity  


- Calibrations    



The conference will be held in the beautiful Istituto degli Innocenti, Piazza SS Annunziata, in Florence and will allow both virtual and in-person participation.