Supernova explosions, also known as 'standard candle' (or type Ia) supernovae, are among the most intense phenomena in the Universe, occurring when a dense white dwarf star subsumes another star. Scientists believe they've discovered the first trace of a supernova on Earth.
The assertion is based on a thorough examination of the alien Hypatia stone discovered in Egypt in 1996. The chemical makeup and patterning of the rock, among other things, indicate that the shards include dust and gas cloud remnants from an Ia supernova.
According to the researchers, that combination of dust and gas would have solidified over billions of years, finally producing the parent body from which Hypatia descended somewhere around the time our Solar System was formed.
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| A 3-gram sample of the Hypatia stone. |
"In a sense, we could say, we have caught a supernova Ia explosion in the act, because the gas atoms from the explosion were caught in the surrounding dust cloud, which eventually formed Hypatia's parent body," says geochemist Jan Kramers of the University of Johannesburg in South Africa.
The researchers examined 17 distinct targets on a small sample of Hypatia using comprehensive, non-destructive chemical analytical techniques. Then it was a matter of putting together information regarding the stone's past and formation.
The rock's exceptionally low levels of silicon, chromium, and manganese indicated that it wasn't created in the inner Solar System. High quantities of iron, sulfur, phosphorus, copper, and vanadium were also discovered, distinguishing the object from anything else in space.
There were significant changes in element concentration patterns in Hypatia compared to what we would anticipate to have evolved in rocks from inside the Solar System and in our Milky Way arm. The theory that the rock evolved from a red giant star is ruled out by further investigation.
The researchers were also able to show that Hypatia didn't match what would be expected if it came from a type II supernova – it has too much iron in comparison to silicon and calcium – leaving the intriguing possibility that this is a remnant from a type Ia supernova, and the first to be discovered on this planet.
"If this hypothesis is correct, the Hypatia stone would be the first tangible evidence on Earth of a supernova type Ia explosion," Kramers argues.
"Perhaps equally important, it shows that an individual anomalous parcel of dust from outer space could actually be incorporated in the solar nebula that our Solar System was formed from, without being fully mixed in."
Type Ia supernovas, based on what we know about them, should create quite odd element concentration patterns in rocks like Hypatia. The scientists couldn't discover a better match for the rock after a thorough review of stellar data and modeling.
Several of the 15 elements found in the stone matched what would be expected if it came from an intense white dwarf star explosion.
However, the case is not yet concluded. Aluminum, phosphorus, chlorine, potassium, copper, and zinc are among the six elements that do not match type 1a supernova predictions. The researchers believe that anything from the supernova's history might explain this.
"Since a white dwarf star is formed from a dying red giant, Hypatia could have inherited these element proportions for the six elements from a red giant star," Kramers explains. "This phenomenon has been observed in white dwarf stars in other research."
More investigation is needed to determine the science, but at this time, it appears that this mystery rock has gone a long way.
