Joel Johansson, Stockholm University
Astronomers have detected a previously unknown supernova explosion more than four billion light years away using a rare phenomenon called “gravitational lensing,” which acts as a kind of cosmic magnifier. They describe their findings and their potential implications in a new paper published in the journal Nature Astronomy.Co-author Ariel Guber, Director Oskar Klein Center At Stockholm University, explained The discovery has been described as “an important step forward in the quest to understand the underlying forces that shape our universe.”
Gravitational lensing is a direct consequence of general relativity. Mass bends and distorts spacetime, so light must follow its curvature. This phenomenon can cause the following effects in rare cases:einstein ring“or”Einstein’s crossEssentially, the space-time distortions caused by massive objects (such as galaxies) act as lenses that magnify background objects. These lenses are not perfect optical quality lenses, so they often have some distortion or unevenness. This causes light from background objects to take different paths to Earth, so a single object can appear in several different locations dispersed around the lens. On a cosmological scale, these paths may require light to travel very different distances to reach it. Earth.
Gravitational lensing helps astronomers discover faint and invisible objects like distant supernovae. This can lead to other interesting questions. For example, last year the astronomer analyzed his 2010 Hubble image, which also happened to catch a supernova. Due to gravitational lensing, this single event appeared in three different places in Hubble’s field of view. Because of this quirk in how the lens works, and because light travels at a finite speed, all three locations looked different. times After the star exploded, researchers connect Even though the supernova was observed more than 10 years ago, the passage of time since then.
This latest paper focuses on a newly discovered supernova called SN Zwicky. Zwicky Temporary Facility (ZTF). The ZTF is a robotic camera attached to the 70-year-old Samuel Osin Telescope. Palomar Observatory in San Diego County. ZTF performs robotic surveys of the night sky, looking for erupting and variable brightness objects such as supernovae, stars eaten by black holes, asteroids and comets. It scans the entire sky over three nights and scans the visible planes of the galaxy twice each night.
Astronomers quickly tagged the object as interesting because it was so unusually bright. He then took advantage of the adaptive optics instruments of three of his other telescopes, the WM Keck Observatory, the Very Large Telescope, and the Hubble Space Telescope, to observe four images of her from different positions in the sky. This confirms that the supernova’s unusual brightness is a product of gravitational lensing.
