As much as half of the calcium in the universe - including what our bones and our teeth contain - is thought to come from supernovae exploding stars, and researchers have now been able to get an unprecedented insight into how these extremely rare, calcium-rich supernovae could reach the end of their lives.

Rare events

An unprecedented view of how these stellar explosions shed so much calcium was made using deep-space x-rays and infrared imaging, and it fills a few of the gaps in our scientific knowledge about the process.

The results of that study were published in The Astophysical Journal, and were presented in a statement issued by Northwestern University on August 5.

By collecting the contributions of 67 authors from 15 countries, the study results indicate that calcium-rich supernovae begin as compact stars that quickly lose mass at the end of their lives, resulting in an outer layer of gas that detonates materials and then collides with them.

"These events are so few in number that we never know what produced the calcium-rich supernova," said astrophysicist Wayne Jacobson-Gallan of Northwestern University in the statement.

The supernova was first observed by amateur astronomer Joel Shepard in the "Messier 100" spiral galaxy M100 (Hubble Telescope)

A supernova rich in calcium

"By observing what this star did in his last month before reaching its critical and tumultuous end, we took a look at a place that had not been explored before and opened new avenues for study in the march of science," said Jacobson-Gallan.

SN 2019ehk was first observed by amateur astronomer Joel Shepard in the "Messier 100 M100" spiral galaxy about 55 million light-years from Earth.

Shortly after its discovery, most of Earth's major telescopes were tracking this supernova. With casual events like this, speed is crucial.

What astronomers did not expect was the brightness of the X-ray light that was given by the "SN 2019ehk" supernova. Scientists soon realized they were looking at a deluge of high-energy X-rays streaming from the star and hitting the outer gaseous envelope, providing key clues as to what material had been discarded and how much material was present.

Readings from the dying star helped scientists figure out what was happening: Interactions between the expelled material and the outer gas ring produced intense temperatures and high pressures, resulting in a calcium-producing nuclear reaction as the star tried to get rid of heat and energy as quickly as possible.

Scientists soon realized that they were looking at a deluge of high-energy X-rays streaming from the star striking the outer gaseous envelope of the supernova (Northwestern University)

The largest amount of calcium

Astronomer Regis Cartier of the National Optical-Infrared Astronomy Research Laboratory (NOIRLab) in the United States comments in the statement posted on the lab's website.

“Most massive stars make small amounts of calcium during their lifetime, but events like SN 2019ehk appear to be responsible for producing massive amounts of calcium and in the process of detonating them through interstellar space within galaxies,” Cartier says. "Ultimately, this calcium finds its way to the formation of planetary systems, and in our bodies as far as our planet," he added.

And it remains that the explosion that occurred at the center of the new study is responsible for the largest amount of calcium that was ever detected in a unique astrophysical event observed. Certainly, being able to see the inner workings of this type of supernova will open up new fields of research and give us a better idea of ​​how calcium appears in our bones, teeth, and everywhere else in the universe.

It is also a great example of the international scientific community working together to capture and record something of great importance. Just ten hours after Joel Shepard discovered the initial bright explosion in the sky, some of the best telescopes were ready to record what happened next.

"Before this event, we had indirect information about what may or may not be calcium-rich supernovae," says astrophysicist Rafaela Margotti, of Northwestern University. "Now we can confidently rule out several possibilities."