{"paper":{"title":"Spitzer Microlens Measurement of a Massive Remnant in a Well-Separated Binary","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.SR","authors_text":"A. Cassan, A. Gould, A. Udalski, B.-G. Park, B. S. Gaudi, B. Wibking, C. Beichman, C. B. Henderson, C. Han, C. Ranc, C. Snodgrass, C.-U. Lee, D.-J. Kim, D. Maoz, D. M. Bramich, E. Bachelet, E. Kerins, G. Bryden, G. D'Ago, G. Pietrzy\\'nski, G. Scarpetta, H. Park, I. A. Steele, I.-G. Shin, I. Soszy\\'nski, J. C. Yee, J. Menzies, J. Skottfelt, J. Skowron, J. Wambsganss, J.-Y.Choi, Keith Horne, K. Ulaczyk, {\\L}. Wyrzykowski, M. D. Albrow, M. Dominik, M. Fausnaugh, M. Friedmann, M. Hundertmark, M. K. Szyma\\'nski, M. Pawlak, P. Mr\\'oz, P. Pietrukowicz, P. Verma, R. A. Street, R. Figuera Jaimes, R. Poleski, R. Schmidt, R. W. Pogge, S. Calchi Novati, S. Carey, S. Kaspi, S. Koz{\\l}owski, S.-L. Kim, S. Mao, S.-M. Cha, Subo Dong, T. Kerr, U.G. J{\\o}rgensen, V. Bozza, W. Varricatt, W. Zhu, Y. K. Jung, Y. Lee, Y. Shvartzvald, Y. Tsapras","submitted_at":"2015-08-26T20:08:06Z","abstract_excerpt":"We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having $M_1>1.35\\,M_\\odot$ (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star or black hole. The system has a projected separation $r_\\perp= 6.1\\pm 0.4\\,{\\rm AU}$ and lies in the Galactic bulge. These measurements are based on the \"microlens parallax\" effect, i.e., comparing the microlensing light curve as seen from $Spitzer$, which lay at $1.25\\,{\\rm AU}$ projected fr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1508.06636","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"}