Researchers have found evidence of a star coming out of its orbit with another star in a “partial supernova”, which is now hurtling through the Milky Way.
The star, which has about 40 percent of the mass of our sun, travels at 559,234 mph.
Scientists from the University of Warwick in the UK point out that the star, a white dwarf designated SDSS J1240 + 6710, has an unusual composition. White dwarfs are tiny, very dense stars that have run out of nuclear fuel.
“Most white dwarfs have atmospheres made up almost entirely of hydrogen or helium, with occasional evidence of carbon or oxygen extracted from the star’s core,” scientists at the University of Warwick explained in a statement. However, SDSS J1240 + 6710 did not appear to contain hydrogen or helium, but was instead composed of an unusual mixture of oxygen, neon, magnesium and silicon, the researchers said.
Scientists were also able to identify carbon, sodium and aluminum using NASA’s Hubble Space Telescope. “However, there is a clear absence of what is known as the ‘iron group’ of elements, iron, nickel, chromium and manganese,” the researchers said in the statement. “These heavier elements are normally cooked from the lighter ones and constitute the defining characteristics of thermonuclear supernovae. The lack of elements of the iron group in SDSSJ1240 + 6710 suggests that the star only went through a partial supernova before the nuclear burn was extinguished. “
The research is published in the Monthly Notices of the Royal Astronomical Society. Scientists from the Universidade Federal do Rio Grande do Sul in Brazil and the Universitat Politècnica de Catalunya in Spain also participated in the project.
“This star is unique because it has all the key characteristics of a white dwarf, but it has very high speed and unusual abundances that make no sense when combined with its low mass,” said Professor Boris Gaensicke, from the Physics Department of the College. Warwick in the statement. “It has a chemical composition that is the fingerprint of nuclear combustion, a low mass and a very high velocity: all of these facts imply that it must come from some kind of nearby binary system and that it must have undergone thermonuclear ignition.”
The star would have been a type of supernova, but of a type not seen before, Gaensicke added.
In a separate project, astronomers in Japan have seen a large “super flame” emerging from a nearby star.
Researchers from Kyoto University and the Japan National Astronomical Observatory detected 12 stellar eruptions on AD Leonis, a red dwarf 16 light-years away. A light year, which measures distance in space, equals about 6 trillion miles.
Red dwarf stars are the smallest and most abundant stars in our galaxy. They are also the longest-running stars.
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