Researchers finally think they know what happened to the star they saw explode 37 years ago

Scientists have finally solved the mystery of Supernova 1987A. It now appears that the star that exploded in 1987 has turned into a neutron star.

It has been very interesting for a long time: Will Supernova 1987A eventually reveal itself as a black hole, or as a neutron star? By observing the ionized argon and sulfur atoms using… James Webb Space Telescope (JWST), astronomers now think they know that it eventually took the form of a neutron star. Scientist Mike Barlow contributed to the research. “We used MIRI and NIRSpec spectrometers to research,” he says. “We were able to identify the strong presence of argon and ionized sulfur. These measurements came from the direct center of the dust cloud hiding the neutron star, providing direct evidence of the existence of a central source of ionizing radiation. Our data show that this cannot be It could be nothing but a neutron star.” The research was published in the journal Sciences.

Supernova 1987A
On February 23, 1987, we observed the explosion of Supernova 1987A here on Earth. Scientists have been observing the supernova for a long time since then, making it one of the most famous and most studied objects in the universe. Supernova 1987A is located 160,000 light-years away, in the center of the so-called Large Magellanic Cloud. A supernova is very special. It is the closest supernova in nearly 400 years. The star that exploded was previously a giant blue-white star, 40 times larger in diameter than our Sun. The explosion of Supernova 1987A released so much light that it was visible to the naked eye in the Southern Hemisphere. Scientists themselves are very pleased with the fact that this was the first supernova in which the formation of a neutron star was successfully predicted.

James Webb
So scientists used the James Webb Space Telescope to search. The space telescope has measuring instruments that can capture infrared light very well, which is very important for this type of research. The large dust cloud currently surrounding Supernova 1987A blocks most of the visible light, which has long left scientists wondering what really happened to the exploded star. Five years ago, scientists thought they had seen something resembling a neutron star, but unfortunately at the time it was difficult to say with complete certainty. Since compelling evidence has now been found for the first time that it is indeed a neutron star, previous predictions can be confirmed with certainty. Our colleague, scientist Claes Fransson, explains: “Thanks to the sharp resolution of the James Webb Space Telescope, we were able to look at the center of the dust cloud for the first time. We now know for sure that there is a built-in source of ionizing radiation. “Using the James Webb Space Telescope, we are now able to confirm the predictions for the first time.”

Supernova
Search results are important. To understand why this is, we first have to go back a few steps to before the supernova happened. To sum it up very briefly: not all stars are created equal. Some stars, like our Sun, will expand slowly at the end of their life cycle. However, this is not the case for stars several times larger and heavier, as was the case with Supernova 1987A. In these stars, gravity plays a major role at the end of their life cycle. These stars do not expand at the end of their lives, but rather collapse due to their enormous mass, eventually leading to a collapse giant The explosion we also call a “Type II supernova.”

These supernovae are very special and of fundamental importance to the universe: during the explosion, the building blocks of the star vibrate so violently that they form entirely new (and often heavier) elements, which are then launched into the universe with tremendous force. blown. What's left after the supernova can vary: either it becomes a neutron star, or the resulting neutron star explodes further and eventually results in a black hole. “Supernovae are the primary sources of the chemical elements that make life possible,” Barlow explains. So it's very important that we make our supernova models clear and work correctly. There are no other objects like the neutron star in Supernova 1987A; A neutron star is very close and only formed recently. The dust cloud has been expanding for some time, which means we will see more and more of the neutron star.

Puzzle piece
However, there is still a small piece of the puzzle that still needs to be put together. It is not yet known exactly where ionizing radiation comes from. Barlow concludes: “There are two possible sources of ionizing radiation. In the first case, the ionizing radiation could come from the surface of the hot neutron star, which currently has a temperature of more than a million degrees Celsius. However, it is also possible that the neutron star is rotating so rapidly that it turns into a pulsar, creating an ionizing wind in the surrounding material by throwing charged particles around it.

There is still a lot to be said about Supernova 1987A. For example, a few months ago the James Webb Space Telescope discovered two strange “crescents” in the dust cloud. Want to know more about this? Then take a look here.