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Since there are countless stars in the universe, one might rightly think that their annihilation would bring spectacular flashes. However, most supernovae are not noticed by the simple observer, as these events are rarely observed in the visible light range. Fortunately, the Hubble Space Telescope detects what the human eye does, so it has been able to record the death of a star 70 million light-years away, writes Science Alert.
In January 2018, a bright explosion shook the edge of the galaxy NGC 2525. A month later, he pointed one of Hubble’s most important instruments, the Wide Field Camera 3, at a phenomenon of light and began photographing it. The work lasted until February 2019, when the light was completely turned off, during which time the research tool managed to capture almost all the phases of the supernova.
The explosion was 5 billion times brighter than the Sun at one time.
“No fireworks on the ground can rival this supernova, whose fading splendor has been recorded by Hubble,” said astrophysicist Adam Riess of the Space Telescope Science Institute and Johns Hopkins University.
At the same time, the supernova in the SN 2018gv catalog is more than just a stellar explosion – it enables astronomers to understand the expansion of the universe. We can speak of the so-called type Ia supernova, which occurs in dual systems in which one of its members is a white dwarf. If this star absorbs too much material from its companion star, it will produce a thermonuclear explosion that will scatter the white dwarf. Since the explosion occurs at a critical mass, these supernovae are, in theory, always equally bright.
Therefore, they can be used excellently for distance estimation, since their absolute brightness is always the same, and this can be determined by comparing it with the apparent brightness.
Measuring distance can help with many things; for example, we can find out how bright galaxies are, but we can also map the distribution of the mysterious dark matter.
Last but not least, we can determine the expansion rate of the universe.
Riess and his colleagues continue to observe SN 2018gv with the Hubble space telescope.
The expert has high hopes for Hubble’s successor, James Webb, who hopes to find even more distant Type Ia supernovae.
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