A space rock may contain the first concrete evidence of a Type Ia . supernova

A strange rock found in Egypt in 1996, known as Hypatia, may contain the first concrete evidence of a Type Ia supernova – one of the rarest and most powerful events in the universe, according to a study by the University of Johannesburg (UJ).

Previous work had already indicated that the space rock was very different from any other extraterrestrial material found in the Solar System, but only now is an in-depth chemical analysis allowing it to more accurately determine its source.

The investigation of the “Hypatia Stone” began in 2013, when Jan Kramers, the study’s lead author, began discovering some unusual evidence in it. The new analysis allowed us to recreate a timeline indicating the formation of the Solar System, except for a few possible scenarios in which the rock would have arisen.

Artist’s concept of a white dwarf “feeding” matter from a red giant (Image: Reproduction/NASA/CXC/M. Weiss)

The study identified a hypothesis. Everything would have started in a binary system, consisting of a red giant star accompanied by a white dwarf. As the dying red giant expanded, the white dwarf began to feed on its substance.

Eventually, the white dwarf exploded as a Type Ia supernova. As the cloud of gases cooled from this event, they began to bind to dust particles around them. The bubble of this substance would have remained isolated from other clouds of dust, retaining information about the powerful and rare phenomenon.

Thousands of years later, the bubble had frozen into a rocky body that might have been Hypatia’s “mother body” at some point in the formation of the solar system. This process would have occurred in the Oort Cloud or the Kuiper Belt, two regions of our planetary system without much internal interference.

Then, Hypatia’s body shot toward the Earth, and during its passage through the atmosphere, the rock shattered until it reached the Great Sand Sea in southeastern Egypt – the impact created the tiny diamonds.

Hypatia analysis

In the first analyzes, in 2013, a study of isotopes of argon revealed that the rocks did not form on Earth. In 2015, another study of the noble gases found in the piece also found that it also did not correspond to any known meteorite or comet.

Small samples size of Hypatia rock compared to a coin (Photo: Reproduction/Jan Kramers)

The researchers also discovered nickel phosphide, a metal that was not found in the solar system. However, the team needed to investigate the rock formation in more detail, but there was no equipment for this.

That’s when study co-author Wojciech Przybylowicz used a proton beam from iThemba Labs to find some chemical patterns in the rock rather than its distortions. Next, the team separated 17 targets in the small sample for analysis in the device, selecting the most isolated parts of the ground minerals.

The researchers found 15 different elements with greater accuracy. “This gave us the chemical ‘ingredients’ we needed,” said George Pelyanin, co-author of the work. And with that, they moved on to the next step: analyzing the entire data set from these analyses.

Discard potential assets

The most significant evidence was the very low level of silicon in the rock, which is added to chromium and manganese, and represents less than 1% of the expected concentration for something formed in the interior of the Solar System. Another interesting feature is the anomalous extreme fright of iron, sulfur, phosphorous, copper and vanadium.

Samples analyzed by the proton beam (Photo: clone/Georgi Plyanin)

This pattern differs from any composition of organisms from the primitive or present solar system. Asteroid belt objects and meteorites also do not match these characteristics. So the researchers went to investigate beyond our planetary system.

They compared the concentration of elements in Hypatia to what would be expected in the interstellar dust of the arm of the Milky Way galaxy in which Earth is located. “Again, there was no similarity,” Kramers added.

Therefore, Hypatia did not form on Earth, nor is it part of any known type of comet or meteorite, let alone something that emerged from intermediate dust within a planetary system or nearby interstellar environment. The proton beam data also ruled out a mass flow from a red giant.

That’s because Hypatia is rich in iron, but poor in silicon and other elements heavier than iron. So the researchers went on to investigate the formation of the rock with another cosmic phenomenon, a Type II supernova – a relatively common event.

violent event

Type II supernovae were also excluded as a source of hypatia formation, as there was too much iron compared to concentrations of silicon and calcium – elements common in supernovae of this type. So the researchers began investigating another, more violent event.

Type Ia supernovae are the main ironmakers in the universe (Image: Reproduction/U TEXAS/CXC/NASA)

Type Ia supernovae are so rare that they occur once or twice per galaxy every century. This phenomenon is responsible for the production of most of the iron in the entire universe – on Earth, most of this element originated from supernovae of this type.

White dwarfs are known to be stable for long periods of time and never explode. However, when a white dwarf feeds on material from a nearby red giant, it eventually becomes heavier, hotter, and unstable, so it explodes in a Type Ia supernova.

Most of the elements in the samples are consistent with predictions of Type I supernovae (Image: Reproduction/Jan Kramers)

According to the researchers, the nuclear fusion that occurred during this explosion should create very unusual patterns of element concentration, which are consistent with currently accepted theoretical models. That is, the best model for the formation of Hypatia is the supernova Ia.

If the hypothesis is correct, this means that the space rock contains the first direct evidence of a Type Ia supernova ever found. The discovery will also reveal how an anomaly of dust from outer space merged into the Solar System, but without mixing.

Submit your research in the journal Icarus.

Source: Icarus via Phys.org

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