Same Supernova Observed Four Times Thanks To Gravitational Lensing

Same Supernova Observed Four Times Thanks To Gravitational Lensing


Astronomers have discovered four separate images of the same distant supernova arranged in the shape of a cross. They now believe that this unusual trick of the light could help them test the structure of the cosmos.

Using NASA’s Hubble Space Telescope, astronomers from the University of California, Berkeley, have spotted for the first time a distant supernova split into four images by cosmic lens. They stated that a massive galaxy within a cluster of galaxies that are gravitationally bending and magnifying light has created four separate images of a distant supernova. They added that the so-called ‘Einstein cross’ will allow a unique study of a distant supernova and the distribution of dark matter in the lensing galaxy and cluster.

Patrick Kelly, of the University of California, also a member of the Grism Lens Amplified Survey from Space (GLASS) collaboration, and who discovered the supernova while looking through infrared images taken by the Hubble Space Telescope (HST), said, “Basically, we get to see the supernova four times and measure the time delays between its arrival in the different images, hopefully learning something about the supernova and the kind of star it exploded from, as well as about the gravitational lenses.”

The astronomers added that when the four images will fade away, they will have a rare opportunity to catch a rerun of the supernova. This is because the current four-image pattern is only one part of the lensing display. The supernova may have appeared as a single image some 20 years ago elsewhere in the cluster field and it is expected to reappear once more within the next five years. The astronomers stated that this prediction is based on computer models of the cluster, which describe the various paths the supernova light is taking through the maze of clumpy dark matter in the galactic grouping.

Astronomers believe that the unique discovery will help them to estimate the amount and distribution of dark matter in the lensing galaxy and cluster. Dark matter cannot be seen directly but is believed to make up most of the universe’s mass. The gravity from both the elliptical galaxy and the galaxy cluster distorts and magnifies the light from the supernova behind them, which is an effect called gravitational lensing.

The findings were published in the Science journal.