%0 Generic %1 kelly2017individual %A Kelly, Patrick L. %A Diego, Jose M. %A Rodney, Steven %A Kaiser, Nick %A Broadhurst, Tom %A Zitrin, Adi %A Treu, Tommaso %A Perez-Gonzalez, Pablo G. %A Morishita, Takahiro %A Jauzac, Mathilde %A Selsing, Jonatan %A Oguri, Masamune %A Pueyo, Laurent %A Ross, Timothy W. %A Filippenko, Alexei V. %A Smith, Nathan %A Hjorth, Jens %A Cenko, S. Bradley %A Wang, Xin %A Howell, D. Andrew %A Richard, Johan %A Frye, Brenda L. %A Jha, Saurabh W. %A Foley, Ryan J. %A Norman, Colin %A Bradac, Marusa %A Zheng, Weikang %A Brammer, Gabriel %A Benito, Alberto Molino %A Cava, Antonio %A Christensen, Lise %A de Mink, Selma E. %A Graur, Or %A Grillo, Claudio %A Kawamata, Ryota %A Kneib, Jean-Paul %A Matheson, Thomas %A McCully, Curtis %A Nonino, Mario %A Perez-Fournon, Ismael %A Riess, Adam G. %A Rosati, Piero %A Schmidt, Kasper Borello %A Sharon, Keren %A Weiner, Benjamin J. %D 2017 %K lensing star %T An individual star at redshift 1.5 extremely magnified by a galaxy-cluster lens %U http://arxiv.org/abs/1706.10279 %X Galaxy-cluster gravitational lenses can magnify background galaxies by a factor of up to ~50. An individual well-aligned background star, however, could potentially become much more highly magnified. Here we report an image of a star (dubbed "MACS J1149 Lensed Star 1 (LS1)") at redshift z=1.49 magnified by >2000. We measure fluctuations in the star's flux arising from microlensing by intracluster stars and compact objects, whose effective Einstein radii should become exaggerated by a factor of ~100 by the cluster's potential. LS1's light curve is sensitive to the mass function of intracluster stars and compact objects and provides evidence about binary fractions as well as specific stellar evolution and supernova models, and against a high abundance of ~30 solar-mass primordial black holes. A second event, separated by 0.26" from LS1, likely corresponds to LS1's counterimage demagnified for multiple years by a ~3 solar-mass object in the cluster. Additional monitoring should test the hypothesis that dark matter consists of extremely light bosons.

@misc{kelly2017individual, abstract = {Galaxy-cluster gravitational lenses can magnify background galaxies by a factor of up to ~50. An individual well-aligned background star, however, could potentially become much more highly magnified. Here we report an image of a star (dubbed "MACS J1149 Lensed Star 1 (LS1)") at redshift z=1.49 magnified by >2000. We measure fluctuations in the star's flux arising from microlensing by intracluster stars and compact objects, whose effective Einstein radii should become exaggerated by a factor of ~100 by the cluster's potential. LS1's light curve is sensitive to the mass function of intracluster stars and compact objects and provides evidence about binary fractions as well as specific stellar evolution and supernova models, and against a high abundance of ~30 solar-mass primordial black holes. A second event, separated by 0.26" from LS1, likely corresponds to LS1's counterimage demagnified for multiple years by a ~3 solar-mass object in the cluster. Additional monitoring should test the hypothesis that dark matter consists of extremely light bosons.}, added-at = {2017-07-03T11:09:46.000+0200}, author = {Kelly, Patrick L. and Diego, Jose M. and Rodney, Steven and Kaiser, Nick and Broadhurst, Tom and Zitrin, Adi and Treu, Tommaso and Perez-Gonzalez, Pablo G. and Morishita, Takahiro and Jauzac, Mathilde and Selsing, Jonatan and Oguri, Masamune and Pueyo, Laurent and Ross, Timothy W. and Filippenko, Alexei V. and Smith, Nathan and Hjorth, Jens and Cenko, S. Bradley and Wang, Xin and Howell, D. Andrew and Richard, Johan and Frye, Brenda L. and Jha, Saurabh W. and Foley, Ryan J. and Norman, Colin and Bradac, Marusa and Zheng, Weikang and Brammer, Gabriel and Benito, Alberto Molino and Cava, Antonio and Christensen, Lise and de Mink, Selma E. and Graur, Or and Grillo, Claudio and Kawamata, Ryota and Kneib, Jean-Paul and Matheson, Thomas and McCully, Curtis and Nonino, Mario and Perez-Fournon, Ismael and Riess, Adam G. and Rosati, Piero and Schmidt, Kasper Borello and Sharon, Keren and Weiner, Benjamin J.}, biburl = {https://www.bibsonomy.org/bibtex/2f0449560a908690d8c1d23d4765bb7a2/miki}, description = {[1706.10279] An individual star at redshift 1.5 extremely magnified by a galaxy-cluster lens}, interhash = {3ddc94d1832ff6314a825f3adb61b973}, intrahash = {f0449560a908690d8c1d23d4765bb7a2}, keywords = {lensing star}, note = {cite arxiv:1706.10279Comment: Submitted on May 18, 2017. Comments welcome}, timestamp = {2017-07-03T11:09:46.000+0200}, title = {An individual star at redshift 1.5 extremely magnified by a galaxy-cluster lens}, url = {http://arxiv.org/abs/1706.10279}, year = 2017 }