Description
Chair: Melina Poulain
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Alexander Mustill (Lund University)28/05/2026, 12:00Poster
When stars evolve, their expanding radii should destroy all planets, asteroids and comets within a few astronomical units. However, many white dwarfs show evidence of planetary material on very short-period (<~1 day) orbits, or deposited into the stellar atmosphere, giving insight into the end states of planetary systems like our own. I will present an overview of our understanding of such...
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Jess Kocher (Malmö University)28/05/2026, 12:01Poster
The origin of multiple populations in globular clusters is very much an open question today. In part, this is an issue of observational data: Small studies vary strongly in method, making it difficult to compare their results, while large-scale spectroscopic survey pipelines are unreliable for chemically peculiar stars. Thus, there is simply not enough reliable data to check theories against....
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Karlis Pukitis (University of Latvia)28/05/2026, 12:02Poster
Virtually nothing is known about the stellar wind in post-AGB phase despite it contributing to evolutionary rate of the star and formation of the subsequent planetary nebula. Near-infrared region of post-AGB star spectra remains unexplored in high-resolution. Of particular interest are CO molecular lines that probe outer atmospheric layers where outflows are expected to form. I will present...
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Heleri Ramler (University of Tartu)28/05/2026, 12:03Poster
Accurate stellar parameters are essential for interpreting exoplanetary systems and, in particular, for exploiting the atmospheric survey that will be carried out by ESA’s Ariel mission. Ariel will observe the atmospheres of roughly one thousand exoplanets using a tiered survey strategy, and requires a precise and homogeneous characterisation of host stars across a broad parameter range before...
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Šarūnas Mikolaitis (Vilnius University)28/05/2026, 12:04Poster
In this contribution, we present a project specifically dedicated to conducting a comprehensive, homogeneous, and precise analysis of the abundances of carbon, nitrogen, and oxygen (CNO) in a large set of stars belonging to all main Galactic stellar populations. We are using the results to investigate the chemical enrichment history of these elements and explore the effects of evolutionary...
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Vladas Šatas (Vilnius University)28/05/2026, 12:05Poster
We present results from an ongoing high-resolution spectroscopic survey of hot subdwarf stars observed with the Vilnius University Echelle Spectrograph (VUES) mounted on the 1.65 m telescope at Molėtai Astronomical Observatory in Lithuania. Building on our previous large-scale study of ~20,000 Gaia XP spectra, we use medium-high-resolution (R≈36,000) optical spectra to derive atmospheric...
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Veronika Mitrokhina (Tartu Observatory of the University of Tartu)28/05/2026, 12:06Poster
Deuterium (D) was primarily produced during Big Bang Nucleosynthesis, with a primordial abundance of [D/H] = (2.58 ± 0.13) × 10⁻⁵ (Cyburt et al. 2016). Deuterium is easily destroyed in stellar interiors through nuclear fusion making its detection in stellar atmospheres unlikely unless external processes, such as planetary engulfment, temporarily enhance surface abundances. A-type stars, with...
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Roar Holmberg (Nordic Optical Telescope and Aarhus University)28/05/2026, 12:07Poster
In the field of asteroseismology, solar-like oscillations are mostly observed using either photometry or radial velocity (RV) from high-resolution stellar spectra. A third option is to measure variations in flux in stellar absorption lines in the spectrum that are sensitive to changes in temperature at the surface of the star.
The first detection of solar-like oscillations in any star other...
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Carlos Viscasillas Vázquez (Vilnius University)28/05/2026, 12:08Poster
Stellar ages remain one of the most difficult parameters to determine in astrophysics. Chemical clocks based on s-process–to–α element abundance ratios offer a promising alternative, but require a robust calibration. We derived asteroseismic ages for 218 F–K giant stars observed in and around the TESS Northern Continuous Viewing Zone using the PARAM and BASTA codes. High-resolution spectra...
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Hua Xiao (University of Turku)28/05/2026, 12:09Poster
We present timing and spectral analysis of XMM-Newton observations of the Be/X-ray pulsar 4U 0115+63 following its 2023 giant outburst. In the quiescent state, we detect coherent X-ray pulsations with a high pulsed fraction (>50%) but no significant low-frequency red noise, indicating the absence of active accretion. The spectrum is well described by a single blackbody with a small emitting...
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