In spite of the major advances that have been made in the understanding of the structure and evolution of the Milky Way, thanks to the Gaia satellite and synergic spectroscopic surveys from the ground, the evolution of the three elements carbon, nitrogen and oxygen, is not yet completely understood. These elements are among the main nucleosynthesis products of core-collapse supernovae as well as of lower mass stars and their abundance is crucial for the hydrogen burning through the CNO cycle. They are of paramount importance also for the cooling of gas clouds that form stars and as building blocks of the complex organic molecules that precede the formation of prebiotic species. Though a large effort is deployed to measure chemical abundances in complement to Gaia by ground-based spectroscopic surveys like WEAVE, 4MOST and MOONS,complementary observations are still in demand to determine the abundances of the CNO elements and their isotopic ratios. We shall take charge of this task.

Program

November 25, 2024

14:00 D. Romano Welcome and contours of the project / Self-presentations by people in the audience (in presence and remote)

14:20 H.-G. Ludwig Formation of molecular lines in the light of 3D hydrodynamical simulations

14:40 E. Caffau Carbon isotopic ratios in extremely metal-poor stars

15:00 J. Alazzawi Oxygen abundances in a sample of very metal-poor stars

15:20 Coffee break

16:00 L. Lombardo CNO abundances and mixing in young massive giants

16:20 L. Monaco (remote) C and O abundances in Open Clusters Blue Straggler Stars

16:40 A. Mucciarelli C and N abundances in a sample of lower RGB stars

17:00 M. Steffen CO5BOLD model atmospheres of metal poor stars: impact of 3D effects on CH line
formation

November 26, 2024

9:50 M. Spite CNO abundances in a sample of metal- poor dwarfs from [Fe/H] = -2 to [Fe/H] = -3.5, from molecular bands

10:10 P. Bonifacio Proposal for project structure and documentation management

10:30 Coffee break

11:00 D. Aguado (remote) Galactic Archaeology and the Future with Canary Observatories

11:20 M. Rossi (remote) Exploring the evolution of CNO chemical elements across different environments

11:40 D. Romano CNO and S isotopic ratios across the Milky Way disc

12:10 P. Panuzzo Black Holes and Neutron Stars with Gaia, Results and perspectives

12:50 Lunch break

14:00 B. Barbuy (remote) CNO molecular lines in the H-band

14:20 F. Rizzuti (remote) Explaining the low 12C/13C ratio at the dawn of chemical evolution

14:40 Shaunak Mishra (master student) Potential of Gaia GRVS magnitudes for estimating metallicities

15:00 Discussion session What emerges from the observations-model predictions comparison: which observations do we need?

15:30 Coffee break

16:00 Y. Zou (PhD student, remote) Determinations of CNO and S isotopic abundance ratios in Galactic molecular clouds

16:20 Hands-on session Presentation of proposals submitted to measure 12C/13C in (i) a sample of M-dwarf stars and (ii) a sample of subgiant stars / Extension of the samples? Extension to other facilities? / Ideas for N measurements / Proposal preparation

November 27, 2024

9:30 Hands-on session Proposal preparation / Large Program?

10:30 Coffee break

11:00 Wrap-up session Team Database / Next steps

13:00 End of meeting