The explosion in 1843 is a new form

Eta Carinae - the biggest, brightest and perhaps most explored star after the sun - holds a secret. Its tremendous explosion seemed to be completely dominated by a weaker form than a conventional supernova without destroying the star.

In the September 11 issue of Nature, astronomer Nathan Smith proposed that the 1843 historic explosion of star Eta Carinae essentially produced a shockwave similar to a true supernova even though a little stronger . The much-recorded event occurring in the Milky Way is probably related to a group of faint stellar explosions in other galaxies discovered in recent years through telescopes during the search process. supernovae in the galaxy. Smith, a postdoctoral researcher at the University of California Berkeley, said: 'There is a group of stellar explosions in other galaxies, although we don't know the cause, but Eta Cariane is the star starter. '.

Eta Carinae (η Car) is a very large and hot transform star, visible only from the southern hemisphere. It lies about 7,500 light-years from Earth in a star-forming region called the Carina Nebula. It was observed that the image glowed so strongly in 1843, astronomers today witnessed the cloud of dust and gas formed after that event, known as the Homunculus nebula, radiating away from home. star. The faint crust containing fragments from the explosion is also visible, probably dating back about 1000 years ago. Perhaps the wind of the star swept away, so the dusty gas layer moved slowly, with a speed of about 650 km / s (1.5 million miles / h) or slower, when compared to the shell of a supernova.

With an 8-meter Gemini South international telescope and a 4-meter diameter Blanco telescope belonging to Cerro Tololo Inter-American observatory in Chile, Smith's observations brought something new: extremely fast air fibers moving 5 times faster than debris in the Homunculus nebula, they were pushed away from Eta Carinae in the same event. According to Smith, the total mass of the Homunculus slow-moving nebula is very consistent with what the wind of a distant star might affect. The much stronger, faster materials he discovered also brought more tough problems to current theories.

Instead, the speed and energy that reminds us of matter is accelerated by the powerful shockwave of a supernova explosion.

The rapid speed of the wave could be doubled earlier than Eta Carinae's forecast for liberating energy in the 1843 explosion of the Eta Carinae - an event that Smith thinks is not just a silent surface explosion. The labyrinth is coordinated by the stellar wind, which is in fact an explosion from deep inside that causes the debris to crash into the universe. In fact, the fast-moving shockwave that collides with slow-moving clouds from a 1,000-year-old explosion that emits X-rays has been observed at the Chandra observatory.

'These observations force us to change our understanding of what happened in the explosion in 1843. It is not a steady wind that blows the outer layer but an explosion from deep within the throne. how to remove the outer shell To have a grave like this requires a new mechanism. '

Shocked from the 1843 explosion of star Eta Carinae.Today a slow moving shell is formed from an explosion that occurred 1000 years ago.The tremor created a bright firework display, heating the outer shell to make it emit X-rays (orange).The Homumculus two-lobed nebula, the slow-moving dust gas shell, was also born from the explosion in 1843, located near the ultra-hot green super-star.(Photo: Cook Lynette / Gemini Observatory)

If what Smith thinks is true, then super-giant stars like Eta Carinae can blow up a large amount of their material in prehistoric explosions as they reach the end of life before one The destructive supernova blew it into pieces and formed a black hole. The explosion is much more faint than a supernova that has generated a rapid wave of movement around Eta Carinae, which is quite similar to the faint star explosion that is sometimes called the "supernova impersonator". . Such stellar explosions have now been discovered in other galaxies thanks to a robot telescope located on Earth and through supernova hunting. This could help astronomers understand the process of expansion in the universe.

'Observing other galaxies, astronomers can see stars like Eta Carinae getting brighter but not as bright as a real supernova. We don't know what that is. It is like a mystery and the reason why the star glows like that without destroying it completely. ' Eta Carinae is a rare super-giant star in our galaxy, which probably has 150 times the mass of the sun . Big stars burn brightly for only a few million years, all the mass lost in the form of intense light will follow the stellar wind. After two to three million years, Eta Carinae currently has a mass of about 90 to 100 solar masses, losing about 10 solar masses alone in the most recent 1843 explosion.

"These explosions are probably the basic way in which large stars can remove the outer layers of hydrogen before they die," Smith said . If Eta Carinae can split 10 solar masses every thousand years, this is an effective way to remove a large mass of a star. ' Astronomers believe that Eta Carinae and other luminous blue stars at the end of life will burn hydrogen in bugs to form helium. If they explode while still holding the hydrogen shell covering the helium core, the resulting supernova will be much different from the supernova that was born when the star removed all the hydrogen before it exploded.

According to Smith, whether supernovae is a miniature version of a supernova, supernovaes have failed, the pre-event of all kinds of different explosions is still unclear. 'This can be an important clue to understanding the last strong stages in the lives of big stars'. Astronomers have not been able to predict the fate of stars sitting more than 30 times the mass of the sun.

Observations published in the Nature include the spectrum obtained from the Blanco telescope (US National Optical Astronomical Observatory - NOAO), and the infrared analog spectrum obtained from the Gemini South telescope. . Both telescopes are located in the Andes (Chile) at an altitude of nearly 9000 feet. NOAO and Gemini Observatory are run by the Astronomical University Association. The research was funded by the National Aeronautics and Space Administration in collaboration with the National Science Foundation.