Andrea Miglio: Updates on HAYDN + galactoarcheology

credits: Gaia Sky, Gaia DR3 Alma Mater Università di Bologna Istituto Nazionale di Astrofisica University of Birmingham Andrea Miglio ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background TASC9 / KASC16 Workshop 7 July 2025 Updates on HAYDN + galactoarchaeology credits: Gaia Sky, Gaia DR3 Alma Mater Università di Bologna Istituto Nazionale di Astrofisica University of Birmingham Andrea Miglio ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background TASC9 / KASC16 Workshop 7 July 2025 Updates on HAYDN + galactoarchaeology ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background change in 15 years CoRoT: 2009 ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background change in 15 years CoRoT: 2009 Kepler: Gaia DR3 + APOGEE+asteroseismology internal structures orbital parameters photospheric chemical composition + He core H-burning shell H-rich radiative core acoustic mode gravity mode ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background understanding the formation and evolution of galaxies observation of objects at high redshiftslarge-scale hydrodynamical simulations of the Universe ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background understanding the formation and evolution of galaxies observation of objects at high redshiftslarge-scale hydrodynamical simulations of the Universe detailed study of the Milky Way: Galactic archaeology use stars as fossils to reconstruct the assembly and chemo-dynamical history of the Galaxy ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background understanding the formation and evolution of galaxies observation of objects at high redshiftslarge-scale hydrodynamical simulations of the Universe wavelength [nm] 860 2-D 3-D 5-D 6-D +12-D Gaia astrometry Spectroscopy position parallax proper motions radial velocity chemical composition + 850 detailed study of the Milky Way: Galactic archaeology use stars as fossils to reconstruct the assembly and chemo-dynamical history of the Galaxy ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background understanding the formation and evolution of galaxies observation of objects at high redshiftslarge-scale hydrodynamical simulations of the Universe wavelength [nm] 860 2-D 3-D 5-D 6-D +12-D Gaia astrometry Spectroscopy position parallax proper motions radial velocity chemical composition + 850 ages chronology 140 180 160 frequency [μHz] + asteroseismology detailed study of the Milky Way: Galactic archaeology use stars as fossils to reconstruct the assembly and chemo-dynamical history of the Galaxy ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background assembly history and evolution of the galaxy asteroseismic ages are commonly used to train data-driven spectroscopic age estimates for hundreds of thousands of stars. Leung et al, Anders et al, Ciuca et al, Almannaei et al, Nepal et al, Casali et al , Zhang et al, Patil et al, Boulet et al., Mackereth et al. + many more papers using ages ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background age-chemical composition low metallicity stars Larsen et al. 2025 Lindsay et al. 2025 Huber et al. 2024 Deheuvels et al. 2012 nothing “wrong” with seismology at least when using individual mode frequencies finally we see potential limitations to the scaling (about time!) νmax e.g. below [Fe/H]~-2 above [Fe/H]~-1.6 Montalban et al. 2021 Chaplin et al. 2020 Larsen et al. 2025 ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background calibrators: Masses radii and Ages: how precise and how accurate? 4 A. Miglio et al.: PLATO as it is: a legacy mission for Galactic archaeology 0.9 1 1.2 1.5 2 3 108 109 1010 Mass (Msun) Age (yr) Thin disk, RGB stars, ν max < 350 µHz Age ∝ M−3.2 [Fe/H] −0.6 −0.4 −0.2 0 0.2 0.4 RR Lyrae solar-like oscillators NGC6811 NGC6819 NGC6791 M4 M67 Cepheids Fig.1 Age-mass-metallicity relation for red giants in a trilegal (Girardi et al. 2005) synthetic population representative of thin-disk red-giant-branch (RGB) stars observed by Kepler. The dashed line indicates the average power-law relation between age and mass of RGB stars. Given their extended mass range and the tight age-mass relations, solar-like oscillating giants (dots) probe the full history of the Milky Way. The asteroseismic age scale is currently being validated primarily thanks to the detection of oscillations in giants belonging to open and globular clusters observed by Kepler and K2 (Arentoft et al. 2017; Brogaard et al. 2016, 2012; Handberg et al. 2017; Miglio et al. 2016; Molenda-˙ Zakowicz et al. 2014; Sandquist et al. 2016; Stello et al. 2016). Classical pulsators in similar evolutionary phases (Cepheids and RR Lyrae stars) are also indicated in the diagram. Asteroseismology, i.e. the study and interpretation of, and the astrophysical inference from global oscillation modes in stars, provides the way forward. Along with enabling exquisite tests of stellar models, pulsation frequencies of the solar-like oscillators may be used to place tight constraints on the fundamental stellar properties, including radius, mass and evolutionary state (see, e.g., Chaplin & Miglio 2013, Christensen-Dalsgaard 2016, Hekker & Christensen-Dalsgaard 2016, and references therein). Stellar mass is a particularly valuable constraint in the case of giants, since for these stars there is a very tight relation between age and mass. The age of low-mass red-giant stars is largely determined by the time spent on the main sequence, hence by the initial mass of the red giant’s progenitor (⌧MS /M/L(M)/M(1), with ⇠4, where Lis the typical luminosity of the star on the main sequence, e.g. see Kippenhahn et al. 2012). With asteroseismic constraints on the stellar mass, it is now possible to infer the age of thousands of individual stars, spanning the entire evolution of the Milky Way (see Fig. 1). One of the most convincing (and highly-regarded) statements about the importance of asteroseismology for Galactic archaeology can be found in the ESO-ESA Working groups Report 4 on Galactic populations, Chemistry and Dynamics (Turon et al. 2008). This working group was requested by ESO and ESA to consider projects that would complement the Gaia mission. One of the recommendations made to ESA was: “Asteroseismology: this is a major tool to complement Gaia with respect to age determinations. ESA should encourage the community to prepare for a nextgeneration mission, which would sample the di↵erent populations of the Galaxy much more widely than CNES-ESA’s CoRoT and NASA’s Kepler”: PLATO is the mission that can deliver long-sought constraints to models of the Milky Way assembly and evolution. The combination of Gaia and spectroscopic surveys will be able to tell us the di↵erence between photometrically defined thick and thin disks vs. chemically defined ↵-rich and ↵-poor disks (for a discussion regarding the various definitions of the thick and thin disks see e.g. Kawata & Chiappini 2016; Minchev et al. 2015). Age information of turn-o↵ stars will be available in the Gaia era. However, these stars are intrinsically faint, preventing a large volume coverage of the Galaxy (e.g. see Cacciari et al. 2016). For giants the current age estimates are very uncertain (for instance those based on C and N spectral features, e.g. Martig et al. 2016; Masseron & Gilmore 2015) and more precise age estimates mainly rely on relatively small asteroseismic data sets from Kepler (Borucki et al. 2010), K2 (Howell et al. 2014) and CoRoT (Baglin et al. 2006; CoRoT Team 2016). What is needed is more reliable and homogeneously derived age information for a much larger number of stars, covering larger volumes of the Milky Way. It has now been demonstrated that precise and more accurate (although still stellar-model dependent) ages can be inferred for the solar-like pulsating red giants observed by the space-borne telescopes CoRoT, Kepler, and K2 (see e.g. Anders et al. 2017b; Casagrande et al. 2016; Miglio et al. 2013; Rodrigues et al. 2017). The combination of chemical compositions from spectroscopic surveys with distances and motions from Gaia and ages from asteroseismic data, on large samples of stars, will allow us to comprehensively study chemodynamical distributions and their time evolution in di↵erent directions of the Milky Way. A recent application demonstrating the potential of such a combination was recently presented by Anders et al. (2017a), where around 400 stars from just two of the CoRoT fields that have measurements with APOGEE spectra (and hence velocity and chemical information) have been used to estimate the evolution of the abundance gradients in the thin disk in the last 6-8 Gyrs, a long-sought constraint to the chemical evolution of the Milky Way. A further example is given by the discovery of the so-called young-↵-rich stars (Chiappini et al. 2015; Martig et al. 2015), i.e. stars with masses implying young ages, but which feature an overabundance in ↵-elements, typical of old stars. It is still unclear whether the large numbers of young-↵-rich stars found so far is compatible with the assumption of them being just blue stragglers, rather than genuine young stars (Fuhrmann et al. 2017; Jofr´ e et al. 2016). In addition, it will finally be possible to map the thick and thin disk components also Copyright line will be provided by the publisher NGC6866 clusters Gaia parallaxes detached EBs e.g. Khan et al., Huber et al., Zinn et al. e.g. Brogaard et al., Gaulme et al, Thomsen et al, Buldgen et al, Joergensen et al., Beck et al. Brogaard et al, Tailo et al., Stello et al.,Li et al, Miglio et al, Handberg et al., Howell et al. SEE TALK BY STELLO ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background Khan et al. 2019,2023ab, see also Hall et al., Huber et al., Zinn et al., Prada Moroni et al. % level radius (distance) determination ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background APOGEE DR17 KIC10001167 Thomsen et al. 2025, A&A, in press seismic and orbital masses agree to within 1.4% (~1σ) Masses radii and Ages: how precise and how accurate? ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background lower quality data K2, TESS several biases related to frequency resolution and realisation noise e.g. Mackereth et al, 2021, Hon et al. 2021, Warfield et al. 2024,Marasco et al. 2025, Theano Theodoris 2025 Willett et al., under review ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background lower quality data K2, TESS several biases related to frequency resolution and realisation noise e.g. Mackereth et al, 2021, Hon et al. 2021, Warfield et al. 2024,Marasco et al. 2025, Theano Theodoris 2025 Willett et al., under review encouraging results in clusters, also in GCs, at least for low-lum stars Tailo et al. 2022, Howell et al. 2022,24,25 ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background RGB Mass loss from mass to age: several systematics [Fe/H] dependence comparison with GCs Brogaard et al., 2024 ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background RGB Mass loss from mass to age: several systematics [Fe/H] dependence comparison with GCs Brogaard et al., 2024 ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background RGB Mass loss from mass to age: several systematics [Fe/H] dependence comparison with GCs Brogaard et al., 2024 physics behind mass loss (eventually) see also Li 2025, submitted ASTERO CHRONOMETRY ASTERO CHRONOMETRY Logo on white background Logo on dark background what about in a composite population? binary stars and products of binary evolution: how to spot them from mass to age: several systematics “young -rich stars” α over/undermassive stars in clusters e.g. unreasonably old stars e.g. Chiappini 2015, Martig 2015, Jofré et al 2016, Izzard et al. 2017, 2018, Hekker&Johnson 2019, Miglio et al. 2021, Silva-Aguirre 2018, Grisoni 2024, Brogaard et al., 2015, 2018; Stello et al., 2016; Handberg et al., 2017 in supposedly simple stellar populations CoRoT, Kepler-K2 TESS designed primarily for planet searches: wide field, bright targets, large pixel sizes PLATO haydn: the context have demonstrated the potential of asteroseismology (in clusters) observational strategy not optimised for stellar / galactic science overcome these limitations i.e. a simple mission concept strongly based on heritage from CoRoT, Kepler, and the knowledge being developed for PLATO by measuring the frequencies of hundreds or thousands of stars that belong to controlled environments or key building blocks of galaxies Voyage 2050 Senior Commi�ee: Linda J. Tacconi (chair), Christopher S. Arridge (co-chair), Alessandra Buonanno, Mike Cruise, Olivier Grasset, Amina Helmi, Luciano Iess, Eiichiro Komatsu, Jérémy Leconte, Jorrit Leenaarts, Jesús Mar�n-Pintado, Rumi Nakamura, Darach Watson. Voyage 2050 Final recommenda�ons from the Voyage 2050 Senior Commi�ee May 2021 24 would provide only an incomplete picture if not accompanied by a precise determination of the internal structure. The core size and physical state, as well as the mantle viscosity and the crust-mantle interaction are essential to decipher its geological evolution, and understand the mystery of why Venus lacks a dynamo. Venus’ moment of inertia, 𝑘 Love number and tidal phase lag are key measurements that a Medium mission to Venus must carry out to a sufficient precision to constrain the interior structure, tackling with the right data sets the adverse effects of the large thermal tides and the recently discovered irregularities of the rotation rate. 3.1.7 High Precision Astrometry Astrometry has significantly contributed to our understanding of the Universe, from the smallest scales of planetoids in the Solar System to very distant quasars. ESA has a history of precision astrometry, beginning with the breakthrough mission Hipparcos, and we are currently experiencing major breakthroughs particularly in Galactic astronomy thanks to the global astrometric ESA space mission, Gaia. This mission is impacting the extent of our knowledge in many fields of astrophysics, ranging from exoplanets and star formation, to the formation and evolution of the Milky Way itself as well as in fundamental physics. The next steps in space astrometry could be either to improve by one order of magnitude the relative astrometric accuracy, or to extend global astrometry to a different wavelength domain, i.e. the near-IR. High precision relative astrometry at the level of sub-μas can probe dark matter in galactic environments and the detection and full characterisation of the orbital architecture of exoplanetary systems with habitable planets orbiting the nearest stars to the Sun. Substantial technology developments in a number of critical areas would be needed in order to reach the highest required precision of 0.2 μas. Global astrometry in the near IR as described in Section 2.2.2 would have a much broader impact as it would tackle various aspects of the above questions, as well as additional important open questions regarding the whole Milky Way ecosystem. Such a mission, which is of Large class given its scientific breadth, will be difficult to scale down to fit the Medium mission cost cap given the technological developments required for the near-IR detectors. However, all of its science objectives could be achieved with a Medium mission led by ESA with a substantial contribution from other partners. Among other possibilities, the US could contribute with the near-IR detector following a similar scheme as in the Euclid mission. 3.1.8 High Precision Asteroseismology Asteroseismology is one of the most powerful tools for probing the structure of stars. It uses the variability of the light from the star produced by its pulsation modes to constrain the interiors of stars. Its final aim is to determine the physical properties and the internal structure of stars, such as how temperature, pressure, density, speed of sound, and chemical composition vary with radius. In the last decade, the research field of asteroseismology has experienced a revolution with the operation of several space missions whose main aim has been the detection of exoplanets, for example Kepler. A Medium mission designed to carry out pure asteroseismology would characterise stars in a wider range of (relatively homogeneous) stellar environments such as dwarf galaxies or the Galactic bulge, as well as Red Giant Branch stars that are relatively close to the Sun. Such missions would provide key information on stellar physics that would allow testing of stellar evolution models, especially when 2-D and 3-D modelling become widely implemented. Furthermore, and in combination with Gaia and large ground-based 25 spectroscopic surveys, they would provide new insights into the star formation history and different phases of the assembly of the Milky Way. 3.1.9 The Role of the Multiphase ISM in Star Formation and Galaxy Evolution Understanding how star formation proceeds in galaxies remains one of the major goals in the theory of galaxy evolution. Observations of the interstellar medium (ISM) are key to deciphering the physical processes regulating star formation in galaxies. The physical processes that transform the overall galactic gas content, such as gas accretion and outflows, regulate star formation in typical nearby galaxies. The accreted gas from the outer regions in the form of ionized or partially ionized gas becomes neutral, cools, and increases its density as it is transported to the galactic inner regions, where it becomes molecular and forms stars, which themselves produce outflows that return material to the ISM. Studying the multiphase structure of the ISM and its evolution will reveal the underlying physical phenomena that set star formation rates and efficiencies. The far-infrared is rich in atomic, ionized, and molecular spectral lines that can directly constrain the physical properties of the different ISM phases and reveal the physical conditions at the transitions between the warm ionized medium, the cold neutral medium, and the self-gravitating cores. The ability of previous farinfrared missions to disentangle the physical properties and the kinematics of the multi-phase ISM has been hampered by their poor spectral resolution and limited spectroscopic mapping capabilities. Far-IR missions with 2-meter class telescopes equipped with multi-beam heterodyne arrays and high resolution (>10 ) spectrometers, can provide large-scale 3D-maps of velocity resolved lines of the dominant gas coolants (e.g. OI, CI, CII, and NII) in our Galaxy and nearby galaxies. The combination of these large-scale maps of key spectral lines will fully characterise the multiphase ISM contributing to a better understanding of the processes that govern star formation in galaxies. 3.1.10 Probing the Violent and Explosive Universe at High Energies: Accretion by Compact Objects and Astroparticle Physics The physics of accretion, acceleration and high-energy particles involves phenomena of great relevance to fundamental physics and in understanding how the Universe was born and how it evolves. Furthermore, multi-messenger astronomy calls for an enhanced synergy between electromagnetic and gravitational wave events. Space-based X-ray and gamma-ray detectors, with improved capabilities with respect to the current generation, such as high-sensitivity, large field-of-view detectors, and/or sensitive keV–MeV spectropolarimetry based on new technologies, will allow us to detect and investigate the most extreme and violent physical phenomena in the Universe and provide a powerful and fundamental synergy with gravitational wave astronomy. Unresolved questions related to explosive nucleosynthesis in stellar explosions, the origin of cosmic rays, accretion and ejection mechanisms in stellar and supermassive black holes and neutron stars, could be solved with missions with these capabilities, as well as boosting the discovery rate of known and unknown rare classes of transient sources throughout the Universe. 20 3 Potential Scientific Themes for Medium Missions Medium missions are a key component of ESA’s Science Programme and enable Europe to conduct relatively stand-alone missions that answer important scientific questions. Although there might be a perceived hierarchy where Large missions carry a higher scientific priority, some scientific questions can be comfortably addressed within a Medium mission envelope and lead to breakthrough science. Naturally, the cost cap limits the available launch vehicles and therefore, for example, the size of platform, diameter of telescope apertures, launch mass and what orbits or interplanetary targets may be reached by a Medium mission, and can also require compromises on payload, instrument resolution, sensitivity, or time resolution. By the design of the Programme, Medium missions are also limited to more mature technology. A past example of an ESA mission that fits comfortably within the Medium mission envelope is Mars Express, and its sister mission Venus Express, both of which have led to breakthrough science at these planets. For example, Mars Express discovered subsurface deposits of water, hydrated minerals that are evidence of liquid water, localised aurorae, and identification of recent glacial landforms helping us to begin to unravel the climatic history of Mars. Venus Express has returned the first indirect evidence of ongoing volcanic activity on Venus. Ariel, ESA’s fourth Medium mission is dedicated to characterising the chemistry and thermal structure of hundreds of transiting exoplanets to move beyond the detection of exoplanets to their characterisation as planetary bodies. Medium missions also provide a route for Europe’s participation in missions with international partners. The Huygens probe, whose cost of M€ 360 was of the order of a Medium mission, is a clear example of ESA participating as a minor partner. Huygens was the first landing of a spacecraft on the natural satellite of another planet and was able to answer questions about the origin of Titan’s atmosphere, the thickest atmosphere of any moon in the Solar System and the only other body apart from Earth that has a thick nitrogen atmosphere, by examining isotopic ratios. It also provided part of the evidence for Titan’s subsurface oceans via the identification of Schumann resonances in the atmosphere. ESA’s participation in the James Webb Space Telescope is a prime example of where a Medium level participation will result in an enormous scientific return for ESA Member State scientists over a wide range of science themes. Within Voyage 2050, there are many examples where scientific themes can be completely encapsulated within a Medium class mission. For example, and without indicating a priority, much work can be done on the foundations of quantum mechanics and general relativity by testing the equivalence principle and probing the structure of space-time. Another example from our recommendation is to probe the intergalactic medium in absorption, which will search for missing baryonic matter and examine the gas cycle in and around galaxies, exploring the role of the galactic environment on star formation. A Large mission would enable a mission to probe the intergalactic medium in emission and would reach a larger fraction of the hidden baryonic matter, but a Medium mission on this theme would still yield breakthrough science in this area. Below we list science themes for Medium missions that arose from discussions within the Topical Teams and the Senior Committee. This list is separated into 14 themes that could be led by ESA within a typical Medium mission envelope and four themes where ESA could participate at the Medium mission level in other agencies' large missions. The list spans the full breadth of the ESA Science Programme, and demonstrates that the community has more than enough excellent ideas to fill as many Medium calls as requirements and design drivers Notional observing schedule Mission Definition Review passed in September 2023ESA M7 CALL Mission Definition Review passed in September 2023 but.. did not make the cut to PhaseA in M7 strengthen, revise and expand the science case consolidate the consortium ESA M8 Call (Mar 2025) - submitted first-step proposal in May 2025 ESA M7 CALL high-precision stellar astrophysics, From the oldest low-mass stars to massive stars that serve as progenitors of GW sources and major contributors to chemical enrichment SO1 stellar cluster evolution and formation, anchoring the stellar age scale to the percent level SO2 assembly history of the Milky Way’s bulge and dwarf galaxies. SO3 investigate how the occurrence and characteristics of exoplanets depend on the properties of their environment. SO4 radically improve our understanding of the main building blocks of cosmic structures Enable a fundamental shift from precise to accurate stellar model predictions, unlocking the full potential of large, high-precision datasets across multiple observational domains. high-precision asteroseismology in dense stellar fields thanks to HAYDN’s science and payload consortium, in particular: Karsten Brogaard Gael Buldgen Lisa Bugnet Angela Bragaglia Cristina Chiappini Margarida Cunha Marc-Antoine Dupret Rafa Garcia Daisuke Kawata Patrick Eggenberger Juan Carlos Suarez Robert Szabo Leo Girardi Laurent Gizon Andy Moya Benoit Mosser get in touch if interested, science consortium is open to ideas and contributions! high-precision asteroseismology in dense stellar fields