A hypernova reaches temperatures of hundreds of millions to billions of degrees Kelvin (or Celsius), existing as superheated plasma where nuclei and electrons separate, making it one of the universe's hottest and most energetic events, significantly hotter and more powerful than a regular supernova. These extreme temperatures facilitate nuclear reactions, creating heavy elements and generating powerful jets, often linked to Gamma-Ray Bursts (GRBs). YouTube +2
A hypernova explosion typically has a mechanical energy output of ~ 10^53 ergs, or about a factor of 100 greater than a supernova.
A supernova reaches around 10 billion degrees Celsius (18 billion F). But that's not the end. If you keep adding heat, the heated plasma will eventually reach the Hagedorn temperature, which is 1.7 trillion (1012) Kelvin.
The first hypernova observed was SN 1998bw, with a luminosity 100 times higher than a standard Type Ib. This supernova was the first to be associated with a gamma-ray burst (GRB) and it produced a shockwave containing an order of magnitude more energy than a normal supernova.
A kilonova is far more powerful. It happens when two neutron stars — the dense remnants of dead stars — collide.
T Coronae Borealis nova 2025: bottom line
During the eruption, the star will temporarily rival the brightness of the North Star! This is possibly a once-in-a-lifetime experience – the next time T Coronae Borealis will brighten up won't be for another 80 years.
This means that the sound energy would be enough to vaporise the Earth. A kilonova is smaller, by a factor of 10 to 100, so 420 to 430 decibels, and a hypernova (really just a very large supernova) might be bigger by a factor of 10, so about 450 decibels.
Ultranova (スーパービッグノヴァ, Sūpā Biggu Nova, lit. "Super Big Nova") is a larger version of the Supernova used by Meta-Cooler Core in Dragon Ball Heroes.
But even that's cooler than Quasar 3C273, the hottest known object in existence, blazing at an astonishing 18 trillion°F (10 trillion°C) as matter spirals into its supermassive black hole. Source: NASA, CERN, and Astrophysical Journal data on black holes, quasars, and cosmic plasma (2025).
Both types are extremely powerful, sending energetic radiation and blast waves of ejected gas far into space. If a supernova explosion were to occur within about 25 light-years of Earth, our planet would probably lose its atmosphere, and all life would perish.
As temperatures rise to about 5,500–6,000 K, stars appear yellow or white. Their light is spread more evenly across the visible spectrum, creating a balanced, pale color. These stars are often stable and long-lived. The hottest stars burn at 10,000 K or more and shine blue or blue-white.
Its estimated radius is about 2,150 times that of the Sun-so immense that if it were placed at the center of our solar system, its surface would extend beyond the orbit of Saturn. Despite its vast size, Stephenson 2-18 has a relatively cool surface temperature of around 3,200 K, which is typical for red supergiants.
The Torch can release all of his body's stored energy in one intense, omni-directional "nova-burst," which can reach about 1,000,000 F, and which is similar to the heat-pulse of a nuclear warhead detonation, with an area of total devastation of about 900 feet in diameter and the power of a super nova.
Although they would be extremely visible, if these "predictable" supernovae were to occur, they are thought to pose little threat to Earth. It is estimated that a Type II supernova closer than eight parsecs (26 light-years) would destroy more than half of the Earth's ozone layer.
The resulting supernova, now known as SN 1054, shone brighter than Venus and remained visible in broad daylight for nearly a month. It left behind the Crab Nebula and a rapidly spinning neutron star — the Crab Pulsar — which continue to expand and emit across the electromagnetic spectrum to this day.
Supernovas in other galaxies might still be visible to the naked eye, but wouldn't look like anything special, and unless you know exactly where to look, you won't be able to tell them from a normal star anyway. If you want to turn yourself into a supernova hunter, you can start checking the best candidates so far.
Sounds between 170-200 dB are so intense that they can cause lethal issues like pulmonary embolisms, pulmonary contusions, or even burst lungs. As for exploding heads, you can expect that from sounds above 240 dB. However, such high intensity sounds are very rare.
Yes, astronomers were eagerly anticipating the recurrent nova T Coronae Borealis (T CrB), known as the "Blaze Star," to "explode" (flare up) as a bright nova in 2025, making it visible to the naked eye for the first time since 1946, though predictions varied from March to later in the year and even 2026/2027, but it's an exciting, predictable event in the Corona Borealis constellation, not a destructive supernova, where a white dwarf brightens dramatically before returning to normal.
By mid-2023, it had faded by 0.35 magnitude or about 28%; its lowest brightness seen since 2016. A similar dimming occurred in the year before the 1946 outburst, suggesting an eruption before September 2024. As of January 2026, such a nova has not yet been observed, although some have predicted it is imminent.
Can life survive? There is no way for life to survive on the surface of a planet witnessing a supernova. As shown above, a habitable planet orbiting Betelgeuse will lose at least 4 km of its surface, vaporized to space.
Between late 2024 and early 2025, one star in our galaxy, dubbed ASASSN-24fw, dimmed in brightness by about 97%, before brightening again. Since then, scientists have been swapping theories about what was behind this rare, exciting event.