Predicting the Evolutionary Descendents of Sequence E Stars

StelNet: Hierarchical Neural Network for Automatic Inference in Stellar Characterization

Characterizing the fundamental parameters of stars from observations is crucial for studying the stars themselves, their planets, and the galaxy as a whole. Stellar evolution theory predicting the properties of stars as a function of stellar age and mass enables translating observables into physical stellar parameters by fitting the observed data to synthetic isochrones. However, the complexity of overlapping evolutionary tracks often makes this task numerically challenging, and with a precision that can be highly variable, depending on the area of the parameter space the observation lies in. …

大质量分层三星系统的详细模拟——探究恒星物理对大质量分层三星系统演化路径的影响

Detailed Simulations of Massive Hierarchical Triple Star Systems - Exploring the impact of the stellar physics on the evolutionary pathways of massive hierarchical triple systems

本研究耦合Tres与Mesa代码首次开展大质量三星系统详细模拟，发现快速恒星代码与详细代码的演化预测存在显著差异，对引力波源形成及星族合成研究有重要启示。

Exploring masses and CNO surface abundances of red giant stars

A grid of evolutionary sequences of stars in the mass range $1.2$-$7$ M$_{\odot}$, with solar-like initial composition is presented. We focus on this mass range in order to estimate the masses and calculate the CNO surface abundances of a sample of observed red giants. The stellar models are calculated from the zero-age main sequence till the early asymptotic giant branch (AGB) phase. Stars of M $\leqslant$ $2.2$M$_{\odot}$ are evolved through the core helium flash. In this work, an approach is adopted that improves the mass determination of an observed sample of 21 RGB and early AGB stars. Th…

CNO dredge-up in a sample of APOGEE/Kepler red giants: Tests of stellar models and Galactic evolutionary trends of N/O and C/N

Surface abundances of C, N, and O in red giants are affected by processed material mixed into the stars' convective envelopes. Using a sample of $\sim 5100$ stars with elemental abundances from APOGEE and asteroseismic masses from {\it Kepler}, we test theoretical stellar models that predict this mixing, then apply these models to derive birth C, N, and O abundances for these stars. Our models with standard mixing can reproduce the observed trends to within plausible uncertainties in the birth abundances. Some models with ''extra'' mixing processes fail, predicting trends with surface gravity …

V404 Cyg系统的演化模型

An evolutionary model for V404 Cyg system

本文利用双星演化模型拟合V404 Cyg的观测参数，给出初始质量、轨道周期、吸积比例与金属丰度约束，并指出黑洞可能具有初始自转。

恒星碰撞的机器学习方法。I. 预测SPH模拟的结果

Machine Learning Methods for Stellar Collisions. I. Predicting Outcomes of SPH Simulations

本文提出利用机器学习预测恒星碰撞结果，通过训练模型实现高精度的碰撞预测和残余质量估计，为N-body模拟提供高效工具。

解码系外行星的未来：星震学对亚巨星和红巨星宿主星的确认

Decoding the Future of Exoplanets: Asteroseismic Confirmation of Subgiant and Red Giant Hosts

本研究利用星震学精确测量五颗类太阳振荡系外行星宿主星的偶极重力模周期间距，确认其处于亚巨星或红巨星支阶段，为预测行星被膨胀宿主星吞没的命运及理解恒星与行星系统演化提供了关键依据。

基于Gaia XP光谱预测（碳增丰）贫金属星的金属丰度与碳丰度

Predicting metallicities and carbon abundances from Gaia XP spectra for (carbon-enhanced) metal-poor stars

本研究利用神经网络结合Gaia XP光谱预测千万级恒星的金属丰度与碳丰度，识别出约2000颗高置信度碳增丰贫金属星，验证了富碳星比例的金属丰度依赖规律，为富碳恒星族群研究提供了均一样本。

Deep Learning Classification in Asteroseismology

In the power spectra of oscillating red giants, there are visually distinct features defining stars ascending the red giant branch from those that have commenced helium core burning. We train a one-dimensional convolutional neural network by supervised learning to automatically learn these visual features from images of folded oscillation spectra. By training and testing on \textit{Kepler} red giants, we achieve an accuracy of up to 99\% in separating helium-burning red giants from those ascending the red giant branch. The convolutional neural network additionally shows capability in accuratel…

Fundamental properties of core-collapse Supernova and GRB progenitors: predicting the look of massive stars before death

We investigate the fundamental properties of core-collapse Supernova (SN) progenitors from single stars at solar metallicity. We combine Geneva stellar evolutionary models with initial masses of Mini=20-120 Msun with atmospheric/wind models using CMFGEN. We provide synthetic photometry and high-resolution spectra of hot stars at the pre-SN stage. For Mini=9-20 Msun, we supplement our analysis using publicly available MARCS model atmospheres of RSGs. We employ observational criteria of spectroscopic classification and find that massive stars, depending on Mini and rotation, end their lives as r…

PARSEC 中质量介于中等至超大质量恒星的演化轨迹、喷出物与电离光子

Evolutionary tracks, ejecta, and ionizing photons from intermediate-mass to very massive stars with PARSEC

本文利用更新后的 PARSEC V2.0 代码计算了从 2 到 2000 太阳质量、金属丰度跨度广泛的恒星演化轨迹，提供了残骸质量、化学喷出物及电离光子数据，并验证了与观测的一致性。