2026-06-28T20:16:10Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/121022023-08-27T15:30:02Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Pérez González, Pablo Guillermo author otros, ... author 2018-04 Galaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to similar to 50. Here we report an image of an individual star at redshift z = 1.49 (dubbed MACS J1149 Lensed Star 1) magnified by more than x 2,000. A separate image, detected briefly 0.26 '' from Lensed Star 1, is probably a counterimage of the first star demagnified for multiple years by an object of greater than or similar to 3 solar masses 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, including binary fractions and specific stellar evolution and supernova models. Dark-matter subhaloes or massive compact objects may help to account for the two images' long-term brightness ratio. 2397-3366 10.1038/s41550-018-0430-3 https://hdl.handle.net/20.500.14352/12102 http://dx.doi.org/10.1038/s41550-018-0430-3 https://arxiv.org/abs/1706.10279 https://www.nature.com/ Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens