A big star once blew up.
It made a very bright light. We saw it from Earth. It was far away in space. This light helps us learn. Can you look at the stars?
A big star blew up in space.
This made a bright light. We saw it from Earth. It was in a small group of stars.
This light was very bright. It was brighter than a big star. We saw the light in 1987.
Tiny bits of light reached us first. These bits are called neutrinos. They arrived before the bright light.
The star was a blue supergiant. It was very large. Now, a small star stays in the middle.
This event helps us learn. We can study how stars die. It is a big discovery.
In 1987, a huge star exploded in space. This event is called SN 1987A. It happened in a small galaxy near ours.
Before the bright light arrived, tiny particles reached Earth. We call these particles neutrinos. They arrived about two or three hours early. This was the first time we saw them from a supernova. It helped us start a new way to study space.
The star that blew up was a blue supergiant. This is a very large, blue star. After it exploded, a small, heavy object may have stayed behind. This is called a neutron star. Scientists found more evidence for this in 2019 and 2021.
The explosion also made special gases. The James Webb Space Telescope saw argon gas near the center. This gas glows because of the neutron star.
Around the center, there are bright rings of dust. The explosion hits these rings. This makes the rings glow with X-rays. The rings might fade away by the year 2030. This event helps us learn how stars die.
In 1987, a massive star exploded in a galaxy near our own. This event was named SN 1987A. It happened in the Large Magellanic Cloud, which is a small galaxy near the Milky Way.
This was the closest supernova seen from Earth since a famous one in 1604. It was a Type II supernova, which is a specific kind of star explosion. This event was special because modern scientists could study it in great detail. It helped us understand how stars collapse and die.
Before the bright light reached us, tiny particles arrived first. These particles are called neutrinos. They reached Earth on February 23, 1987. The neutrinos arrived about two or three hours before the visible light.
This happened because neutrinos are released during the core collapse. The light must wait for a shock wave to reach the star's surface. This discovery marked the start of neutrino astronomy. It showed that 99% of the energy from a collapse is released as neutrinos.
Scientists discovered this explosion in several ways. Ian Shelton and Oscar Duhalde found it in Chile. At the same time, Albert Jones found it in New Zealand.
The star that exploded was a blue supergiant. This was a surprise to many researchers at the time. They found that the star's blue color came from its chemical makeup. The star had very low levels of heavy elements. Some think the star might have merged with a companion star before it died.
After the explosion, the debris stayed hot and bright. This glow comes from radioactive decay.
Elements like nickel-56 and cobalt-56 provided the energy for the light. Now, the glow is powered by the decay of titanium-44. Astronomers also see bright rings of material around the center. These rings were made by the star before it exploded. The explosion's shock wave hits these rings and makes them glow with X-rays.
We are still finding new things inside the remains. For a long time, the neutron star at the center was hard to find.
In 2019, telescopes found evidence of a neutron star in a dust clump. In 2021, X-ray telescopes found more proof. In 2024, the James Webb Space Telescope saw argon gas near the core. This gas glows because the neutron star shines on it. These discoveries help us see how a dead star's heart works.
SN 1987A was a massive Type II supernova that occurred in the Large Magellanic Cloud. This is a dwarf satellite galaxy located near our own Milky Way.
The explosion reached Earth on February 23, 1987. It was the closest supernova observed since Kepler's Supernova in 1604. This event was a landmark for modern astronomy. It allowed scientists to study a core-collapse supernova in incredible detail. The brightness peaked in May 1987. At its peak, it had an apparent magnitude of about 3. This made it brighter than Alpha Doradus, the brightest star in its constellation.
The discovery of the explosion happened almost simultaneously in different parts of the world. Ian Shelton and Oscar Duhalde found it at the Las Campanas Observatory in Chile. Within the same 24 hours, Albert Jones discovered it in New Zealand.
Later research showed that the star had actually begun brightening as early as February 23. In March 1987, the Astron space telescope observed the event using ultraviolet light. Scientists eventually identified the progenitor, or the original star, as a blue supergiant. This was surprising because most models did not expect a blue supergiant to produce such an explosion. The star's blue color likely came from a chemical composition with very low levels of heavy elements.
A defining feature of SN 1987A was the arrival of neutrinos. These are tiny particles that are released during a core collapse. About two to three hours before the visible light reached Earth, a burst of neutrinos was detected.
Three different observatories recorded these particles: Kamiokande II, IMB, and Baksan. At 7:35 UT, Kamiokande II detected 12 antineutrinos in a burst lasting less than 13 seconds. This event marked the official beginning of neutrino astronomy. The data showed that neutrinos carry away about 99% of the energy from a stellar collapse. These observations helped scientists set limits on neutrino mass and charge. For example, they found the electron neutrino mass is at least 30,000 times smaller than an electron.
The light we see from a supernova comes from radioactive decay. This process keeps the expanding debris hot and glowing for a long time.
Initially, the decay of nickel-56 into cobalt-56 provided the energy for the peak brightness. As the cobalt-56 decayed into iron-56, it powered the light for several months. Later, the luminosity was supported by the decay of titanium-44. This isotope has a half-life of about 60 years. Because of this radioactive heating, the remnant stays visible long after the initial explosion. By measuring these light curves, astronomers can calculate the exact masses of elements created during the explosion.
Surrounding the center of the explosion are three bright rings of material. These rings were created by the stellar wind of the star before it died. The ultraviolet flash from the supernova ionized this material, causing it to glow.
Scientists used trigonometry to calculate the distance to SN 1987A using these rings. They determined the supernova is approximately 168,000 light-years away. Around 2001, the expanding debris, moving at over 7,000 km/s, collided with the inner ring. This collision heated the material and caused a massive increase in X-ray emissions. However, these clumps of matter are slowly being destroyed by the shock wave. Scientists predict the rings may fade away between 2020 and 2030.
For many years, astronomers struggled to find the neutron star at the center. A core-collapse supernova is expected to leave behind a compact object like a neutron star. The Hubble Space Telescope searched for it starting in 1990 but found nothing. Scientists wondered if the star had become a black hole or if dust was hiding it. In 2019, researchers found indirect evidence of a neutron star within a bright dust clump.
In 2021, X-ray telescopes provided further evidence by detecting emissions from a pulsar wind nebula. These findings suggest a compact object is indeed present at the heart of the remnant.
Recent observations have added even more detail to our understanding of the core. In 2024, the James Webb Space Telescope identified ionized argon in the central region. This argon gas is located very close to the remnant's core.
The gas glows because of ionizing radiation coming from the hidden neutron star. This discovery helps confirm the presence of the neutron star through its effect on surrounding gas. SN 1987A continues to be a vital laboratory for studying how stars die and how new elements are born.
Where will your curiosity go next?
🖼️ Images & Media (6)
More to explore
✨ What else?
Related topics you might enjoy
🔬 Go deeper
More advanced topics to explore
🪜 Step back
Simpler topics to build understanding
What is Nepedia?
A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.