Andreas W. Neitzel
CV
Portrait of Andreas W. Neitzel

Andreas W.
Neitzel

Astrophysicist building machine-learning methods for large surveys

I am a fifth-year PhD candidate at the University of Porto and IA, building machine learning for Galactic archaeology. Deep neural networks and unsupervised learning on Gaia and other large surveys let me reconstruct how the Milky Way was assembled. My first-author paper in Astronomy and Astrophysics (2025) led to Starfold, an open-source Python package.

I am principal investigator on two competitive supercomputing allocations, on Deucalion and MareNostrum 5, for JANUS, my neural network for Gaia spectra. I also use Bayesian inference and asteroseismology to measure stellar ages.

Academic CV (PDF)Full record

In the field

VLT platform at sunset, Paranal, May 2024
VLT platform at sunset, Paranal, May 2024
Beneath the mirror cell of a Unit Telescope
Beneath the mirror cell of a Unit Telescope
Speaking at TASC10/KASC17, Aarhus, 2026
Speaking at TASC10/KASC17, Aarhus, 2026
Between the Unit Telescopes in daylight
Between the Unit Telescopes in daylight
Presenting JANUS in Porto
Presenting JANUS in Porto

What I work with

Software engineering

Typed, tested Python packages with continuous integration, locked environments and Sphinx manuals.

Visualisation and web

matplotlib and Plotly figures, and interactive browser applications in WebGL, Canvas2D and SVG.

Machine learning

Normalising-flow ensembles in PyTorch, gradient boosting, manifold learning (UMAP) and density-based clustering (HDBSCAN), with Optuna search.

Uncertainty and reliability

Isotonic calibration of per-star error probabilities, interval-coverage and selection tests, nearest-neighbour novelty for out-of-distribution stars, and covariance propagation through wavelet projections.

Data at scale

Ingestion of whole Gaia releases into Parquet shards, with manifest-resolved datasets, duplicate checks and provenance on every product.

High-performance computing

Slurm on the ARM, x86 and GPU partitions of Deucalion and the University of Bologna clusters, with CUDA and RAPIDS.

Astronomy data and models

Gaia, APOGEE, GALAH, LAMOST, TESS and Kepler data with PARAM, MESA, GYRE, TRILEGAL, galpy and astropy.

By date

202620 entries

  1. Nov 2026to Nov 2027 HPC · principal investigator FCT Advanced Computing Project 2026.08362.CPCA.A2: JANUS on MareNostrum 5, Gaia DR4MareNostrum 5 (Barcelona Supercomputing Center)
  2. Nov 2026to Nov 2027 HPC · principal investigator FCT Advanced Computing Project 2026.08382.CPCA.A1: JANUS on Deucalion, Gaia DR3Deucalion (Minho Advanced Computing Centre)
  3. Oct 2026 paper EPRV asteroseismology of the K dwarfs GJ 570 A and GJ 783 A with ESPRESSO. Empirical mode-amplitude scaling in tension with 3D convection simulationsAstronomy and Astrophysics (published online, volume pending) DOI
  4. Oct 2026 invited talk JANUS: a neural network for APOGEE-like chemistry of the TESS asteroseismic red giants from Gaia XP spectra, with per-star reliabilityIMAS13, 13th Iberian Meeting on Asteroseismology · Cádiar (Granada), Spain
  5. Oct 2026 manual Starfold manualTutorials, how-to guides and one page for every metric of the Starfold package. Open
  6. Sep 2026 poster pitch JANUS poster pitch at ENAA XXXVIENAA XXXVI · Porto, Portugal
  7. Sep 2026 poster JANUS: a machine-learning-based Gaia XP chemistry catalogue for the full TESS asteroseismic red-giant sampleENAA XXXVI · Porto, Portugal
  8. Sep 2026to Aug 2027 fellowship PhD research fellowship under the FCT project ArqueoGalTwelve-month PhD research fellowship paid by the ArqueoGal project.
  9. Jul 2026 talk Contrastive deep learning for structure-preserving chemistry of TESS asteroseismic red giants from Gaia XP spectraTASC10/KASC17, 10th TESS and 17th Kepler Asteroseismic Science Consortium Workshop · Aarhus, Denmark DOI
  10. Jul 2026 poster HAYDNsim: Forecasting photometric noise in the crowded fields that defeat current missionsTASC10/KASC17, 10th TESS and 17th Kepler Asteroseismic Science Consortium Workshop · Aarhus, Denmark DOI
  11. May 2026 proposal · co-investigator PLATO noise estimates for accreted-star candidates for a guest-observer proposalCo-investigator on a PLATO Guest Observer proposal for accreted halo stars, and ran its noise simulations.
  12. May 2026 proposal · co-investigator PLATO noise estimates for the NGC 1851 red-giant guest-observer proposalCo-investigator on a PLATO Guest Observer proposal for NGC 1851 red giants, and ran its noise simulations.
  13. May 2026 proposal · co-investigator PLATO noise estimates for a blue-straggler guest-observer proposal (34 open clusters)Co-investigator on a PLATO Guest Observer proposal for blue stragglers, and ran its noise simulations.
  14. May 2026to present software Tellurion: a laboratory of interactive physics simulationsFree website of interactive physics and astronomy simulations. Open
  15. May 2026 seminar JANUS presentation, Stars DayIA Stars Day 2026, Instituto de Astrofísica e Ciências do Espaço · Porto, Portugal
  16. Apr 2026to present software ArqueoGal integration repositoryPrepares Gaia DR3 and APOGEE DR19 data for the ArqueoGal project's models. Open
  17. Apr 2026to present software Stellar ExplorerBrowser app showing the HR-diagram track and oscillation spectrum of a one-solar-mass star. Open
  18. Apr 2026 talk Simulação fotométrica de enxames estelares densos para o HAYDNDFA Week 2026, Departamento de Física e Astronomia, FCUP · Porto, Portugal
  19. Apr 2026to present software StarfoldFinds groups in a table of measurements and reports how often each group recurs across 32 refits. Open
  20. Feb 2026to Aug 2027 project FCT Exploratory Research Project ArqueoGal: Unraveling the evolutionary history of the Milky Way with Galactic ArchaeologyFCT exploratory project on the Milky Way's history. Developer of its machine-learning pipelines. DOI

20258 entries

  1. Dec 2025to Sep 2026 HPC Deucalion development access, University of Porto HPCvLABDeucalion (Minho Advanced Computing Centre)
  2. Sep 2025 talk Novel Approaches to Galactic Archaeology with Machine LearningENAA XXXV, National Meeting of Astronomy and Astrophysics · Lisbon, Portugal
  3. Sep 2025to Mar 2026 abroad Visiting PhD Student, INAF Osservatorio di Astrofisica e Scienza dello SpazioINAF-OAS Bologna · Bologna, Italy
  4. Sep 2025to Aug 2026 fellowship FCT Doctoral FellowshipDoctoral fellowship from FCT, Portugal's national science funding agency. DOI
  5. Aug 2025 teaching Tutor, Escola de Verão de Física 2025Faculdade de Ciências da Universidade do Porto · Porto, Portugal Open
  6. Jun 2025 teaching Supervisor, IA Summer Programme 2025IA/CAUP · Porto, Portugal Open
  7. Mar 2025 paper · first author Dissecting stellar populations with manifold learning. I. Validation of the method on a synthetic Milky Way-like galaxyAstronomy and Astrophysics, 695, A243 DOI
  8. Jan 2025 data Appendix: Dissecting stellar populations with manifold learning I. Validation of the method on a synthetic Milky Way-like galaxyZenodo DOI

202411 entries

  1. Nov 2024 talk Intelligent Identification of Stellar Populations with Manifold Learning11th Iberian Meeting on Asteroseismology (IMAS11) · Lluc, Balearic Islands, Spain Open
  2. Sep 2024 talk Dissecting Stellar Populations with Manifold LearningENAA XXXIV, National Meeting of Astronomy and Astrophysics · Guimarães, Portugal Open
  3. Aug 2024 teaching Tutor, Escola de Verão de Física 2024Faculdade de Ciências da Universidade do Porto · Porto, Portugal Open
  4. Jul 2024 school Porto Summer School on Asteroseismology, From Pixels to Stellar AgesVila do Conde, Portugal Open
  5. Jul 2024 poster · co-author Small separations in red-giant stars: quest for late evolution signatures using asteroseismologyTASC8/KASC15, 8th TESS and 15th Kepler Asteroseismic Science Consortium Workshop · Porto, Portugal DOI
  6. Jul 2024 talk Identification of stellar populations through latent space projectionTASC8/KASC15, 8th TESS and 15th Kepler Asteroseismic Science Consortium Workshop · Porto, Portugal DOI
  7. Jul 2024 organiser Local Organising Committee member, TASC8/KASC15 workshopTASC8/KASC15, 8th TESS and 15th Kepler Asteroseismic Science Consortium Workshop · Porto, Portugal Open
  8. Jul 2024 teaching Supervisor, IA Summer Programme 2024IA/CAUP · Porto, Portugal Open
  9. May 2024 conference The Milky Way Assembly Tale conference (remote attendance)Remote Open
  10. May 2024 observing Visiting astronomer, ESPRESSO at the VLT, ESO Paranal ObservatoryParanal, Chile Open
  11. Mar 2024 paper Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO: detection of solar-like oscillations in the K5 dwarf epsilon IndiAstronomy and Astrophysics, 683, L16 DOI

20235 entries

  1. 2023 award Best Master's Student in Astronomy and AstrophysicsFaculdade de Ciências da Universidade do Porto · Porto, Portugal
  2. Dec 2023 organiser Chair of the Local Organising Committee, IA Stars DayIA Stars Day · Porto, Portugal
  3. Sep 2023 talk Machine Learning Applied to Galactic ArchaeologyENAA XXXIII, National Meeting of Astronomy and Astrophysics · Coimbra, Portugal Open
  4. Aug 2023 teaching Tutor, Escola de Verão de Física 2023 (The Colours of the Sun)Faculdade de Ciências da Universidade do Porto · Porto, Portugal Open
  5. Feb 2023to present outreach Physics-demonstrations monitor for visiting school groupsFaculdade de Ciências da Universidade do Porto · Porto, Portugal

202211 entries

  1. 2022to present consortium Member, Kepler Asteroseismic Science Consortium (KASOC), Red-Giant Oscillations working group
  2. 2022to present consortium Affiliate, TESS Asteroseismic Science Operations Centre (TASOC)
  3. 2022 organiser Local Organising Committee member, IA Stars DayIA Stars Day · Porto, Portugal
  4. Dec 2022 thesis Determination of age and mass for seismic stars in the Ariel input catalogUniversidade do Porto, Faculdade de Ciências Open
  5. Dec 2022 degree completed MSc in Astronomy and AstrophysicsFaculdade de Ciências da Universidade do Porto · Porto, Portugal Open
  6. Sep 2022 poster Homogeneous Stellar Characterization for the Ariel Space MissionENAA XXXII, National Meeting of Astronomy and Astrophysics · Lisbon, Portugal
  7. Sep 2022to present position PhD Researcher, Stellar Astrophysics GroupIA/CAUP · Porto, Portugal
  8. Sep 2022to present degree in progress PhD in AstronomyFaculdade de Ciências da Universidade do Porto and IA/CAUP · Porto, Portugal
  9. Sep 2022 talk Stellar Characterization for the ARIEL Space MissionFÍSICA 2022, 23rd National Physics Conference (Sociedade Portuguesa de Física) · Porto, Portugal
  10. Jul 2022 paper Ariel stellar characterisation. I. Homogeneous stellar parameters of 187 FGK planet host stars: description and validation of the methodAstronomy and Astrophysics, 663, A161 DOI
  11. Apr 2022 talk Determinação da idade e da massa de estrelas sísmicas no catálogo ArielDFA Week, Departamento de Física e Astronomia, FCUP · Porto, Portugal

20213 entries

  1. 2021to present consortium Member, ESA Ariel Science Consortium, Stellar Characterisation working group (Age, Mass and Radius sub-group)
  2. Sep 2021to Mar 2022 fellowship MSc research fellowship, BreakStarS projectFCT-funded MSc research grant on the BreakStarS stellar-evolution project.
  3. Sep 2021to Mar 2022 position MSc Research Fellow, BreakStarS projectIA/CAUP · Porto, Portugal

20202 entries

  1. Nov 2020 degree completed BSc in Physics (Astrophysics branch)Faculdade de Ciências da Universidade do Porto · Porto, Portugal
  2. Sep 2020 degree started MSc in Astronomy and AstrophysicsFaculdade de Ciências da Universidade do Porto · Porto, Portugal Open

20171 entry

  1. 2017 degree started BSc in Physics (Astrophysics branch)Faculdade de Ciências da Universidade do Porto · Porto, Portugal