Eta Carinae — one of the most misinterpreted stars. 170 years ago, astronomers have taken a series of eruptions on the surface of a supernova. However, to their surprise, the star died. Since then, the windy nature of light seemed to be studied in detail, but the observation of the light echo of ancient blast again raise questions without answers.
Light echo, open about a hundred years ago — is a bright light from a distant event (such as a supernova) reflected from the surrounding dust.
Sometimes he reaches the Earth hundreds of years after the radiation that comes to us directly. Over the last decade, experts have learned to work with this light — to analyze the wavelength and to draw conclusions about the temperature of the material explosion, its composition and the speed with which it was cast forth.
One of these explosions — "great eruption" Eta Carinae, the mass of which is about 100 times more solar. This is one of the most massive binaries Milky Way. Between 1838 and 1858 years, it has lost about one-tenth of its mass, throwing stuff at a speed of 1000 km / s.
Eta Carinae became the prototype of a new class of stars — psevdosverhnovyh. They are heated to at least 7000 K, which leads to flaking and a sudden outburst of the surface material. However, the observation of the light echo, performed by Armin Rest of the Space Telescope Science Institute (USA) and his colleagues have shown that? Kiel during the famous eruption was much colder — about 5 thousand K. In other words, it can not be attributed to psevdosverhnovym.
Augusto Daminelli astronomer from the Institute of Astronomy, Geophysics and Atmospheric Sciences, University of Sao Paulo (Brazil), who discovered that? Keel is actually a binary system is extremely surprised by the result of research: "Any well-educated astronomer was willing to bet that they will find spectrum of the star with a temperature of 7000 degrees Kelvin."
Why eruption happened and why it did not destroy the star? Answers to these questions now no. Perhaps, the explosions were caused by the increased gravitational interaction, when the two stars in the system came close to each other, says Mr. Rest. Mr. Daminelli, however, tends to a different explanation: the high temperature in the core creates electron pairs and their antiparticles — positrons, which quickly recombine. Instability occurs, generating a local explosion.
Only one thing — look for the light echo in other parts of the sky in order to clarify the speed and temperature of the ejected material.
The study is published in the journal Nature.