The insets in this beautiful Hubble image of the MACS 1149 cluster shows the well-known supernova Refsdal, which appears as multiple copies of the same supernova due to strong gravitational lensing by a foreground galaxy. A new study led by Claudio Grillo (University of Milan, Italy and University of Copenhagen, Denmark) has now used the time delay between the multiple images of supernova Refsdal as a means of measuring the Hubble constant, a fundamental cosmological parameter that defines scales like the universe’s size, expansion rate, and geometry. By calculating the Hubble constant using time delays in a lens galaxy cluster, Grillo and collaborators confirm the possibility of an approach independent from techniques previously used to measure the constant. To learn more about their study, check out the article below.
Citation
C. Grillo et al 2018 ApJ 860 94. doi:10.3847/1538-4357/aac2c9