Incredibly hot clumps of gas every two times more massive than Mars, discovered recently the space telescope Hubble in the vicinity of a dying star. And the “cannonade” amazing “cannonballs”, according to astronomers, occurs in these places every eight and a half years for at least the last 400 years.
fireballs – a big mystery for scientists, since the fixed material cannot be ejected from the parent star, called V Hydrae. This star is a bloated red giant that lies 1,200 light years from Earth.
Recall that the red giants are dying stars in the later stages of life. Such luminaries are expanding in size and shed their outer layers into space. If estimates of astronomers are correct, then V Hydrae so got rid of half of their covers.
Scientists believe that the plasma balls were launched invisible companion star. And according to this assumption, that a satellite must travel in an elliptical orbit, which brings him to a bloated atmosphere of a red giant star once every 8.5 years. As soon as this unknown partner is included in the outer atmosphere of the bloated stars, he “swallowed” the material. This material then settles in a disk in orbit around this companion and serves as a launching pad for plasma bolts. The last move at a speed of about 805 thousand kilometres per hour.
Such a system can explain a variety of luminous shapes, discovered the “Hubble” around the dying star, the researchers say. They are called planetary nebula is an expanding shell of luminous at all wavelengths of gas ejected by the star in the last stages of life.
“We assume that these gaseous clumps created during the last stage of life of stars contribute to the appearance of structures seen in planetary nebulae,” says lead study author Ravindra Sahay (Raghvendra Sahai) from laboratory of jet movement of NASA.
Observations of Hubble over the last two decades has demonstrated the enormous complexity and diversity of such structures in planetary nebulae. High resolution telescope has helped to capture the clumps of material and glowing clouds of gas surrounding a dying star.
the Astronomers assume that these clumps was once the jets of material ejected by the companion star. Himself the object was not detected by the telescope. The majority of stars in the milky Way are part of binary systems. However, the details of the process in which these jets arise, remains for scientists a riddle.
“We want to determine what causes these amazing transformation – from a bloated red giant into a beautiful, glowing planetary nebula. Dramatic changes occur in a period of approximately 200-1000 years – the blink of an eye in the cosmic scale,” says Sahay.
the Research team under the leadership Saha used data from the spectrograph of the Hubble space telescope STIS observation of V Hydrae and its surroundings between 2002 and 2004, and then from 2011 to 2013. Spectroscopy allows to decode the information about the light emanating from the object, revealing information about its speed, temperature, location and motion.
the Data showcased a string of incredibly hot balls, each of which had a temperature of more than 9400 degree Celsius. The researchers made a detailed map of the location of objects. “Observations have shown that the balls are moving over time,” says Sahay. STIS recorded giant structure 60 billion kilometers from V Hydrae.
as soon as the balls are moving away, they increase in diameter and cooled, and then become invisible in visible light. But other observations at longer submillimeter waves (helped a network of telescopes Submillimeter Array in Hawaii) showed a fuzzy, confusing structure, which can be balloons, produced about 400 years ago, scientists say.
based On these data, Sahay and his colleagues have developed a model that takes into account the presence of the companion star with the accretion disc, which shows the process of throwing those balls. “Model provides the most plausible explanation, because we know that these jets are produced accretion disks,” explains the scientist.
According to him, the red giants such disks no, but many a companion star is likely to have them. “The ones that supposedly have a slightly lower mass, because they develop a bit slower. The model that we propose explains the presence of bipolar planetary nebulae, the presence of structures, like jets, in many of these objects. We believe that the model will have wide application,” adds Sahay.
the Team hopes to use Hubble for further observation system Hydrae V.
the Results of scientific work published in The Astrophysical Journal.