{"paper":{"title":"Swift observations of the ultraluminous X-ray source XMMU J004243.6+412519 in M31","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"F. Pintore, L. Tomasella, L. Zampieri, P. Esposito, S. E. Motta","submitted_at":"2012-10-18T11:38:52Z","abstract_excerpt":"We report on a multi-wavelength study of the recently discovered X-ray transient XMMU J004243.6+412519 in M31, based on data collected with Swift and the 1.8-m Copernico Telescope at Cima Ekar in Asiago (Italy) between 2012 February and August. Undetected in all previous observations, in 2012 January XMMU J004243.6+412519 suddenly turned on, showing powerful X-ray emission with a luminosity of 1E+38 erg/s (assuming a distance of 780 kpc). In the following weeks, it reached a luminosity higher than 1E+39 erg/s, in the typical range of ultraluminous X-ray sources (ULXs). For at least 40 days the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.5099","kind":"arxiv","version":2},"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"}