Telescope VLT has registered the mysterious disappearance of a massive star
During observations on the Very Large telescope (VLT) the European southern Observatory (ESO) astronomers have discovered the loss of unstable massive stars in dwarf galaxy Kinman. Scientists suggest glitter star could fall sharply as it disappeared behind a cloud of dust. There is another explanation: star collapsed into a black hole without the formation of a supernova. The study is published in the journal Monthly Notices of the Royal Astronomical Society.
Between 2001 and 2011, different groups of astronomers studied a mysterious massive star located in the dwarf galaxy Kinman. Observations showed that the star is in a late stage of its evolution.
Astronomers from Ireland, Chile and the United States decided on its example to learn how to end their life, very massive stars. But when they are in 2019, directed the ESO VLT telescope on this distant galaxy, they found it stars.
"We surprisingly found that the star disappeared! — presented in a press release from ESO, the head of research Andrew Allan (Andrew Allan) from Trinity College in Dublin, Ireland. — It was extremely unusual that such a massive star disappeared without a bright supernova. We first observed as a star, the monster ends his life this way."
Dwarf galaxy of Kinman located approximately 75 million years in the constellation of Aquarius is too far from us, so you can see its individual stars, but to see some signs of their presence. From 2001 to 2011, the radiation from the galaxy are invariably testified to the fact that it is a blue variable star of high luminosity, about 2.5 million times brighter than the Sun. Stars of this type are unstable, they show sharp irregular changes in their spectra and Shine.
In August 2019, the group first explored the star receiver of ESPRESSO, using all four eight-meter telescope of the VLT complex at the same time. But to find signs that previously pointed to the presence of stars of high luminosity, failed. A few months later, the group has used mounted on the same telescope ESO VLT receiver X-shooter, and again to no avail.
The group referred to earlier data obtained with the receivers X-shooter and UVES at the ESO VLT in Chile's Atacama desert and other telescopes around the world.
"Search tools ESO Science archive has allowed us to find and use the data obtained for this facility in 2002 and 2009 — says another employee of the research group of Trinity College Dublin josé Grau (Jose Groh). — Comparing the spectra obtained with high resolution in 2002 with the spectrograph UVES with our observations of 2019, held in ESO designed with the latest high-resolution spectrograph ESPRESSO was particularly significant as the astronomical and technical aspects".
Previous data showed that the dwarf star in the galaxy of Kinman was in the phase of strong flare, which probably ended somewhere around 2011. Such blue stars of high luminosity during their evolution is subjected to the giant outbursts during which the rate of loss of the mass of the peak, and the luminosity increases sharply.
"Perhaps we have registered one of the most massive stars in our region of the Universe," — said Jose Grau.
On the basis of their observations and simulations, astronomers have proposed two possible explanations for the disappearance of the star without a supernova explosion. Flash could be caused by turning the blue variable high luminosity in a star with lower luminosity, and the star could, moreover, be partially hidden by the cloud of dust. Another possibility, according to researchers, could be the collapse of a star into a black hole without a supernova explosion.
Scientists hope that the secrets of the evolution of this and other massive stars will be solved, when will come into operation Extremely Large telescope ESO (ELT), the input of which is planned for 2025. It will have a resolution sufficient to see individual stars in distant galaxies, such as dwarf galaxy of Kinman.