{"paper":{"title":"A stellar-mass BH in a transient, low luminosity ULX in M31?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.HE","authors_text":"((1) INAF -- Osservatorio Astronomico di Padova (2) INAF -- Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano (3) ESA/European Space Astronomy Centre, Fabio Pintore (1), Luca Zampieri (1), Paolo Esposito (2), Sara Motta (3), Villanueva de la Ca\\~nada)","submitted_at":"2013-05-08T15:52:47Z","abstract_excerpt":"We present a multi-wavelenght study of the recently discovered Ultraluminous X-ray transient XMMUJ004243.6+412519 (ULX2 hereafter) in M31, based on Swift data and the 1.8-m Copernico Telescope in Asiago (Italy). Undetected until January 2012, the source suddenly showed a powerful X-ray emission with a luminosity of 1e38 erg/s (assuming a distance of 780 kpc). In the following weeks, its luminosity overcame 1e39 erg/s, remaining fairly constant for at least 40 days and fading below 1e38 erg/s in the next 200 days. The spectrum can be well described by a single multi-color disk blackbody model w"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1305.1862","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"}