José Manuel NievesSEGUIR Updated: Save Send news by mail electrónicoTu name *
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According to a new study from the University of Warwick and recently published in Monthly Notices of the Royal Astronomical Society, the explosion of a white dwarf in the form of “ supernova partial ” did that come out fired from her orbit around another star, and now rush, to more than 900,000 km per hour , through out our galaxy.
The finding leaves open the possibility that there may be many more, “ stars survivors ” supernova traveling through the Milky Way without that astronomers have discovered, in addition to have revealed a strange new type of supernova that astronomers had never seen before.
In their article, the investigators analyzed a white dwarf that you already knew that I had a atmospheric composition unusual. Which reveals that the star probably formed part of a binary system (two stars that orbit each other) and who survived his own explosion as a supernova, something that until now was not thought possible. The outburst made both the white dwarf as its companion came out fired in opposite directions .
white dwarfs are the cores that remain of ancient red giants after his death, during which these massive stars shed into space their outer layers. In this way the white dwarfs, authentic, embers of stars “, is gradually cooling down over billions of years. Most of them have atmospheres composed almost entirely of hydrogen and helium, with traces occasional of carbon or oxygen.
But that is not the case of this star. Designated as a ADSS J1240+6710 , was discovered in 2015 and seemed not to contain hydrogen or helium, but an unusual mix of oxygen, neon, magnesium and silicon. Using the Hubble space telescope, the scientists also identified carbon, sodium and aluminum in the strange atmosphere of the star, materials, all of which occur during the first thermonuclear reactions in a supernova.
however, there is a clear absence of what is known as the “ group iron ” of elements: iron, nickel, chromium and manganese. These heavier elements are normally “cooked” from the most light and are the defining characteristics of supernovae thermonuclear. Its absence in SDSSJ1240 + 6710 suggests that the star just went through one of the typical phases of a supernova, which the researchers have called the “supernova” part.
The astronomers were able to measure the speed of the white dwarf and discovered that travelling to 900,000 miles per hour. It also has a mass particularly low for a white dwarf, only the 40% of the mass of our Sun , which would be consistent with the mass loss from a supernova partial.
Boris Gaensicke , in the Department of Physics of the University of Warwick and lead author of the study, says, “this star is unique because it has all the key features of a white dwarf, but also has that speed so high and an abundance of unusual items that make no sense when combined with its low mass. The star has a chemical composition that is the thumbprint from the combustion of nuclear fuel, a massive low and a very high speed: all these facts imply that it must come from some type of binary system and who must have suffered an ignition thermonuclear. Surely a supernova, but of a type we had not seen before”.
the researchers believe that the supernova destabilized the orbit of the white dwarf around its companion star when he expelled them violently, a large percentage of its mass. Both stars would have been fired in opposite directions of their orbital velocities, in a kind of maneuver slingshot . Which would explain the enormous speed of SDSSJ1240 + 6710.
For Gaensicke, “if we are faced with a binary system of compact, which was subjected to an ignition thermonuclear, expelling much of its mass, we have the conditions necessary to produce a white dwarf of low mass and make it fly at great speed”.
it Is more than probable, therefore, that SDSSJ1240 + 6710 is the survivor of a type of supernova that it was not “caught in the act”. Without the nickel radioactive that feeds the glow of the long duration of the supernovae of Type Ia , the explosion that sent to SDSS1240 + 6710 full-speed through our galaxy would have been a brief flash of light very difficult to discover.
‘ The study of supernovae thermonuclear -add Gaensicke – is a huge field and requires a large amount of observation effort to find supernovae in other galaxies. The difficulty is that you see the star when it explodes, but it is very difficult to know what were the properties of the star before exploding. Now we are discovering that there are different types of white dwarfs that survive the supernovae in different conditions and using the compositions, masses and speeds that they have, we can determine what type of supernova have suffered. Clearly, there is an entire zoo full out there. Studying the remnants of supernovae in our Milky Way will also help us to understand the supernovae that we see in other galaxies”.