12 Einstein crosses
This montage shows the 12 newly discovered quadruply-imaged quasars, also called "Einstein crosses". The fuzzy dot in the middle of the images is the lensing galaxy, the gravity of which is splitting the light from the quasar behind it in such a way to produce four quasar images. By modeling these systems and monitoring how the four different images of the quasar vary differently in brightness over time, astronomers can determine the expansion rate of the Universe and help solve cosmological problems.
The 12 false-colour images are 15 arcsecond on a side. The minimum separation between quasar images in the tightest of these crosses is at the level of ~ 0.5 arcsecond.
The names of the Einstein crosses, from left to right and top to bottom, are: GraL J024848.7+191331, GraL J060710.8-215217, GraL J060841.4+422937, GraL J065904.1+162909, GraL J081828.3-261325, GraL J113100.0-442000, GraL J153725.3-301017, GraL J165105.3-041725, GraL J181730.8+272940, GraL J201749.1+620443, GraL J203802.7-400814, GraL J210329.0-085049.