{"paper":{"title":"The sdA problem - II. Photometric and Spectroscopic Follow-up","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"A. D. Romero, B. G. Castanheira, D. Koester, Ingrid Pelisoli, L. Fraga, S. O. Kepler","submitted_at":"2018-04-24T14:13:09Z","abstract_excerpt":"Subdwarf A star (sdA) is a spectral classification given to objects showing H-rich spectra and sub-main sequence surface gravities, but effective temperature lower than the zero-age horizontal branch. Their evolutionary origin is an enigma. In this work, we discuss the results of follow-up observations of selected sdAs. We obtained time resolved spectroscopy for 24 objects, and time-series photometry for another 19 objects. For two targets, we report both spectroscopy and photometry observations. We confirm seven objects to be new extremely-low mass white dwarfs (ELMs), one of which is a known"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.09059","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}