{"paper":{"title":"Extreme magnification of a star at redshift 1.5 by a galaxy-cluster lens","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Adam G. Riess, Adi Zitrin, Alberto Molino Benito, Alexei V. Filippenko, Antonio Cava, Benjamin J. Weiner, Brenda L. Frye, Claudio Grillo, Colin Norman, Curtis McCully, D. Andrew Howell, Gabriel Brammer, Ismael Perez-Fournon, Jean-Paul Kneib, Jens Hjorth, Johan Richard, Jonatan Selsing, Jose M. Diego, Kasper Borello Schmidt, Keren Sharon, Laurent Pueyo, Lise Christensen, Mario Nonino, Marusa Bradac, Masamune Oguri, Mathilde Jauzac, Nathan Smith, Nick Kaiser, Or Graur, Pablo G. Perez-Gonzalez, Patrick L. Kelly, Piero Rosati, Ryan J. Foley, Ryota Kawamata, Saurabh W. Jha, S. Bradley Cenko, Selma E. de Mink, Steven Rodney, Takahiro Morishita, Thomas Matheson, Timothy W. Ross, Tom Broadhurst, Tommaso Treu, Weikang Zheng, Xin Wang","submitted_at":"2017-06-30T17:18:42Z","abstract_excerpt":"Galaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to ~50. Here we report an image of an individual star at redshift z=1.49 (dubbed \"MACS J1149 Lensed Star 1 (LS1)\") magnified by >2000. A separate image, detected briefly 0.26 arcseconds from LS1, is likely a counterimage of the first star demagnified for multiple years by a >~3 solar-mass object in the cluster. For reasonable assumptions about the lensing system, microlensing fluctuations in the stars' light curves can yield evidence about the mass function of intracluster stars and compact objects, inc"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1706.10279","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"}