The Hubble Telescope captured something amazing 12 years ago. But no one has seen it yet
About 11.5 billion years ago, a red giant star collapsed and exploded, giving rise to a stunning supernova in the early universe.
the main points:
- Supernovas create some of the most powerful explosions in the universe, but they are difficult to detect once they occur
- A team of astronomers has discovered a supernova caused by the death of a red giant star about 11.5 billion years ago.
- This discovery is the first detailed look at how one of these explosions evolved in early stars
Light from the star’s catastrophic death made its way through space and time to finally be captured by the Hubble Space Telescope in 2010.
But it wasn’t discovered until a team of scientists led by Wenley Chen of the University of Minnesota searched the Hubble archives.
“This might be the first supernova to collapse in his heart [yet discovered]Dr. Chen said.
Hubble captured the moments immediately after the star exploded in a series of three images, the team reports today in the journal Nature.
“You can see that it’s developing over hours and days, so it’s a small supernova,” said Patrick Kelly, co-lead author of the study, from the University of Minnesota.
“This is really the first detailed look at individual supernova explosions since the universe was a small part of its age.”
Nature’s magnifying glass captures the past
Detection The supernova at the time of its explosion is difficult enough in the nearby universe, but it is even more difficult for those who exploded not long after the Big Bang.
That’s because light from objects is stretched and shifted to the red end of the spectrum – known as redshift – by the expansion of the universe.
The redder the light becomes, the more difficult it is to detect it by telescopes like Hubble, which have a limited ability to see objects at those longer wavelengths.
So astronomers turn to galaxy clusters, which distort spacetime, bending and amplifying the light coming from stars and galaxies much further away.
The effect results in multiple versions of the same object as light travels through different paths.
Dr. Chen discovered the supernova, which had a redshift corresponding to 11.5 billion years, magnified by a group of closer galaxies known as Abell 370 in the constellation Cetus.
The supernova was what is known as a Core collapse or a Type II supernova, which occurs when a massive star burns all its fuel and blows out and becomes faint. As temperature and pressure rise, it deflates under its own weight, sending out a shock wave.
“We are not able to see this process, because the star’s outer shell is still there, blocking the radiation from the inside,” said Dr. Chen.
When the shock wave reaches the surface of the star, it causes a bright, high-energy explosion that expands and then fades over time as it cools.
Hubble captured this “shock cooling” phase at three different time points, starting five to six hours after the explosion.
The supernova initially appeared blue, then became redder as it rapidly cooled over the course of eight days.
Dr. Chen used the supernova’s brightness and cooling rate to estimate the size of the original star.
According to his calculations, the star was about 530 times the size of our Sun, making it a type of star known as a red giant star.
“Winley’s scale is really amazing, because the individual star was so far away,” said Dr. Kelly.
Live fast die young
Discovering and seeing a distant supernova in its early stage was exciting, said Brad Tucker, an astronomer at Australian National University who has studied much closer cosmic eruptions.
While it’s hard to capture this far, Dr. Tucker said the time-dilation effects caused by the expansion of the universe mean the initial phase can be observed for much longer than a nearby supernova, where the shock cooling ended in a day or two.
“The universe has expanded so much, it has taken much longer for this process to appear,” Dr. Tucker said.
He tells us that the same process that occurs in a “vanilla core collapse supernova” in our local universe, also occurred at the beginning of time.
Giant red planets, which live quickly and die young, sow the evolution of the universe.
“It just shows that these stars, which we know produced some of the heaviest elements in the universe, were around 11 and a half billion years ago,” Dr. Tucker said.
The search is now underway to find more of these stars in the early universe using the James Webb Space Telescope (JWST), which observes objects in infrared wavelengths of light, which is more sensitive to red light.
Dr. Chen and Dr. Kelly both have projects with JWST.
“Given James Webb’s sensitivity, we expect to start seeing more of these [early] Dr Kelly said:
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