{"id":14244,"date":"2017-04-20T14:11:34","date_gmt":"2017-04-20T18:11:34","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=14244"},"modified":"2017-04-20T14:11:34","modified_gmt":"2017-04-20T18:11:34","slug":"hubble-sees-first-gravitationally-lensed-standard-candle-supernova","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=14244","title":{"rendered":"Hubble sees first gravitationally lensed “standard candle” supernova"},"content":{"rendered":"

A galaxy or other massive object can bend light. Light from a star far beyond and behind such an object from our point of view can be bent just like light going through a lens. This lens effect can result in multiple views of the same star. This gravitational lens phenomena has been studied for many years but no one till now has used it to see a special kind of “standard candle” supernova that provides a way to measure distances in the universe. Here is a report on these new observations with the\u00a0Hubble space telescope<\/a>:<\/p>\n

Hubble observes first multiple images of explosive distance indicator<\/a><\/strong><\/p>\n

A Swedish-led team of astronomers used the NASA\/ESA Hubble Space Telescope to analyse the multiple images of a gravitationally lensed type Ia supernova for the first time. The four images of the exploding star will be used to measure the expansion of the Universe. This can be done without any theoretical assumptions about the cosmological model, giving further clues about how fast the Universe is really expanding. The results are published in the journal Science.<\/p>\n

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This composite image shows the gravitationally lensed type Ia supernova iPTF16geu, as seen with different telescopes. The background image shows a wide-field view of the night sky as seen with the Palomar Observatory located on Palomar Mountain, California. The leftmost image shows observations made with the Sloan Digital Sky Survey (SDSS). The central image was taken by the NASA\/ESA Hubble Space Telescope and shows the lensing galaxy SDSS J210415.89-062024.7. The rightmost image was also taken with Hubble and depicts the four lensed images of the supernova explosion, surrounding the lensing galaxy. [Larger images<\/a>]<\/em><\/figcaption><\/figure>An international team, led by astronomers from the Stockholm University, Sweden, has discovered a distant type Ia supernova<\/a>, called iPTF16geu [1]<\/a> \u2014 it took the light 4.3 billion years to travel to Earth [2]<\/a>. The light from this particular supernova was bent and magnified by the effect of gravitational lensing so that it was split into four separate images on the sky [3]<\/a>. The four images lie on a circle with a radius of only about 3000 light-years around the lensing foreground galaxy, making it one of the smallest extragalactic<\/a> gravitational lenses discovered so far. Its appearance resembles the famous Refsdal supernova, which astronomers detected in 2015 (heic1525<\/a>). Refsdal, however, was a core-collapse supernova<\/a>.<\/p>\n