{"paper":{"title":"High-fidelity stellar extinction with Gaia and APOGEE -- I. The method and a new extinction curve","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Stellar extinction for APOGEE stars is measured to 0.03 mag precision by training an XGBoost model on minimally reddened stars and anchoring to a Gaia BP/RP ratio of 1.694.","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"Dennis Stello, Giacomo Cordoni, Haibo Yuan, Hiep Nguyen, Ioana Ciuc\\u{a}, Jie Yu, John A. Taylor, Luca Casagrande, Ronald Drimmel, Shourya Khanna, Tomasz R\\'o\\.za\\'nski, Zhen Yuan","submitted_at":"2026-01-15T17:03:08Z","abstract_excerpt":"The scarcity of high-fidelity extinction measurements remains a bottleneck in deriving accurate stellar properties from Gaia parallaxes. In this work, we aim to derive precision extinction estimates for APOGEE DR19 stars, establishing a new benchmark for Galactic stellar population studies. We first determine reddening by comparing observed colorsr, etrieved from photometric surveys or standardized synthetic magnitudes from Gaia BP/RP spectra, to intrinsic colors predicted via an XGBoost model. The model is trained on minimally reddened stars to infer intrinsic colors and their associated unce"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Our extinction estimates (Av) outperform existing results (Bayestar19, StarHorse, SEDEX), achieving a typical precision of 0.03 mag in Av. Notably, we identify systematic deviations of up to 30% between monochromatic and passband-integrated extinction ratios at wavelengths greater than 700 nm.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that a training set of minimally reddened stars exists and can be reliably identified to train the XGBoost model for intrinsic colors without residual dust bias.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Machine learning derives 0.03 mag precision Av extinctions for APOGEE stars and a new passband-specific extinction curve showing up to 30% deviations from monochromatic ratios beyond 700 nm.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Stellar extinction for APOGEE stars is measured to 0.03 mag precision by training an XGBoost model on minimally reddened stars and anchoring to a Gaia BP/RP ratio of 1.694.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"455beca2e9f4bd87df7992741262ab102a83e27c7423a4972e352b8241cb1d66"},"source":{"id":"2601.10595","kind":"arxiv","version":2},"verdict":{"id":"d4f01be6-8de8-4bdf-954a-a65a300a7c62","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T13:59:38.721466Z","strongest_claim":"Our extinction estimates (Av) outperform existing results (Bayestar19, StarHorse, SEDEX), achieving a typical precision of 0.03 mag in Av. Notably, we identify systematic deviations of up to 30% between monochromatic and passband-integrated extinction ratios at wavelengths greater than 700 nm.","one_line_summary":"Machine learning derives 0.03 mag precision Av extinctions for APOGEE stars and a new passband-specific extinction curve showing up to 30% deviations from monochromatic ratios beyond 700 nm.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that a training set of minimally reddened stars exists and can be reliably identified to train the XGBoost model for intrinsic colors without residual dust bias.","pith_extraction_headline":"Stellar extinction for APOGEE stars is measured to 0.03 mag precision by training an XGBoost model on minimally reddened stars and anchoring to a Gaia BP/RP ratio of 1.694."},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}