Using data pulled in by the Vista Variables in the Via Lactea Survey (VVV) from 2010 to 2014, the astronomers found 655 candidate variable stars of a type called Cepheids.
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European Southern Observatory’s VISTA telescope has enabled astronomers to find a disc of young stars buried behind thick dust clouds in the central bulge of the Milky Way – something that wasn’t found until now. “The youngest Cepheid may even be only around 25 million years old, although we can not exclude the possible presence of even younger and brighter Cepheids”, Dante Minniti of the Universidad Andres Bello, the study’s second author, said in a statement. The VISTA telescope can slice through the thick cosmic dust using infrared rays. These stars are unique in that they expand and contract at regular intervals.
This diagram shows the locations of the newly-discovered Cepheids in an artist’s rendering of our Milky Way Galaxy; the yellow star indicates the position of our Solar System. Their brightness can change dramatically in just a few days or months.
These pulsation periods are extremely regular, and in 1908 the astronomer Henrietta Swann Leavitt discovered that brighter Cepehids had longer pulsation periods, and dimmer Cepheids had shorter periods.
This area of the galaxy was unknown to scientists until now.
Mapping the Cepheids, the team also traced an entirely new feature in the Milky Way – a thin disc of young stars across the galactic bulge. The fact that the Milky Way has created these new celestial bodies baffled the astronomers that discovered them and there is still no explanation as to how they appeared. Cepheids are brighter than most nonvariable stars – several thousand times brighter than Earth’s sun, for example – which makes these stars easier to spot, said Istvan Dekany of the Pontifical Catholic University of Chile.
Researchers have discovered a new component of the Milky Way.
“The central bulge of the Milky Way is thought to consist of vast numbers of old stars”.
Out of 655 Cepheids in the Milky Way’s center, 35 are “classical Cepheids”, which are characterized as young stars, according to the researchers.
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The ages of these classical Cepheids give solid proof that they have been earlier unconfirmed, with constant supply of recently formed stars into the centre of the Milky Way more than the last 100 million years. What he does find surprising, he said, is how ubiquitous the classical Cepheids are in this region.
