arXiv subjects

Dario Fritzewski

Publications and source records attributed to Dario Fritzewski.

3 recordsLinked to original sources

arXiv2026

Large-scale time-series spectroscopy for stellar ages

To date, Galactic Astronomy has largely concerned itself with astrophysical processes, and with the locations, space motions and compositions of objects. Consider, for example, the elucidation of the components of the Galaxy over the past decades, its mapping as enabled by Gaia and its predecessors, the photometric and spectroscopic characterization of innumerable astrophysical objects in various wavelength ranges, both from the ground and from space, and the expanding discovery and characterization of exoplanets; all focused on the current, static Galaxy. This White Paper proposes a dedicated program to derive stellar ages from time-series spectroscopy to hasten the transformation of this static conception into a dynamical one with age-labeled objects and events.

astro-ph.IM↗

arXiv2025

Exploiting tidal asteroseismology in binary populations from combined space photometry and time-resolved high-resolution spectroscopy

Space-based photometry has substantially increased the number of pulsating stars found in binary systems by more than four orders of magnitude. Combined with high-resolution spectroscopy, high-precision photometry offers model-independent constraints on stellar parameters and internal processes. The advent of space-based photometric surveys has given us access to populations of tidally perturbed pulsators, which offer a unique and demanding set of constraints on tidal physics and stellar interiors. However, we lack the ability to undertake multi-epoch, high-resolution spectroscopy at large scale. The ability to obtain phase-resolved, high-resolution spectra would allow us to place precise, model-independent constraints on the stellar properties of pulsators in binary systems that will truly test our close binary asteroseismic modelling techniques, leading to much-needed constraints on fundamental stellar and binary physics. The need to properly cover the large parameter-space of binary stars demands a large-scale, population-level analysis in order to understand the complex landscape of binary stellar evolution. To enable this population-level analysis, we need a dedicated multi-fibre spectrograph (30--200 fibres) with high spectral resolution ($R\geq 50000$), high signal-to-noise ratio ($\mathrm{S/N\geq 300}$), and a limiting magnitude of approximately 15. Such a spectrograph would be capable of efficiently resolving the pulsation variability on the order of minutes and orbit motion on the order of days to years for many targets.

astro-ph.IM↗

arXiv2016

Rotation periods for cool stars in the 4 Gyr-old open cluster M67, the solar-stellar connection, and the applicability of gyrochronology to at least solar age

We report rotation periods for 20 cool (FGK) main sequence member stars of the 4 Gyr-old open cluster M 67 (= NGC 2682), obtained by analysing data from Campaign 5 of the K2 mission with the Kepler Space Telescope. The rotation periods delineate a sequence in the color-period diagram (CPD) of increasing period with redder color. This sequence represents a cross-section at the cluster age of the surface P = P (t, M), suggested in prior work to extend to at least solar age. The current Sun is located marginally (approx. one sigma) above M 67 in the CPD, as its relative age leads us to expect, and lies on the P = P (t, M) surface to within measurement precision. We therefore conclude that the solar rotation rate is normal, as compared with cluster stars, a fact which strengthens the solar-stellar connection. The agreement between the M\,67 rotation period measurements and prior predictions further implies that rotation periods, especially when coupled with appropriate supporting work such as spectroscopy, can provide reliable ages via gyrochronology for other similar FGK dwarfs from the early main sequence to solar age and likely till the main sequence turnoff. The M 67 rotators have a rotational age of 4.2 Gyr, with a standard deviation of 0.7 Gyr, implying that similar field stars can be age-dated to precisions of ~17%. The rotational age of the M 67 cluster as a whole is therefore 4.2 Gyr, but with a lower (averaged) uncertainty of 0.2 Gyr.

astro-ph.SR↗