Astrophysics, the ‘star dance’ in the Milky Way

Binary stars that would give rise to a single more massive star, ‘cradles’ in which almost all stars are formed: they will be studied by INAF researcher Elena Pancino who won a 2.5 million ERC grant

There ‘star dance’ in the Milky Way makes the Italian scientist Elena Pancino, researcher of theNational Institute of Astrophysics, a grant of 2.5 million euros from the European Research Council. The winning project of the Advanced grant is called StarDance and will test observations on the innovative hypothesis according to which many exotic populations – hitherto misunderstood – in star clusters and in the Milky Wayare the result of mass exchange and fusion between pairs of stars.

From next November 1st, and for the following five years, the Inaf researcher in Florence will lead the European StarDance project which, with a budget of two and a half million euros made available by the European Research Council (ERC), the European Council of Research, will try to answer a fundamental question that has been open for decades: “How are stars formed?”.

StarDance will study the physical and chemical properties of exotic stellar populations in star clusters and in the field population of the Milky Way, to prove the new hypothesis proposed by Elena Pancino based on the study of a type of ‘non-canonical’ stars, result of interactions between binary stars that would merge into one more massive star. These populations of stars will be studied above all in star clusters, both open and globular, ie the ‘cradles’ in which most stars form, thus making them very active environments from a chemical and dynamic point of view.

Inaf points out that it is not yet entirely clear what the formation mechanism is for these clusters, especially for the most ancient ones (globular ones), nor if star formation in the early universe was different from what is possible observe today. Some of these exotic stars have been waiting for a certain interpretation of their origin for decades. The definition derives from some of their peculiar characteristics: for example an anomalous chemical composition, the type of rotation or their extreme lithium richness, or the loss of an important part of their atmosphere.

The catchy title of the StarDance project recalls the dance of the stars, a concept often used to describe the path of objects that gravitate around each other. “In my project, I will combine the dance of stars that alone rotate very fast on their axis, binary stars that rotate around each other, and star clusters in which thousands or even millions of stars follow their paths non-deterministic, solitary or in pairs and multiples, under the action of the common gravitational field” explains Elena Pancino.

The Italian researcher underlines that “with StarDance I will have the opportunity to test my new hypothesis, according to which the interactions between stars very close to each other, with mass exchange and also with the merger of the two stars, can explain all the observations in natural and organic way. artificial intelligence, and also requires very varied astrophysics skills”. “In essence, for the first time the problem will be looked at from different angles in an organic way and ranging between different research fields that traditionally do not communicate much with each other” observes Elena Pancino.

This research is part of a scientific context that is already in great ferment in the field of stellar formation and evolution, thanks also to the contribution of the European astrometric mission Gaia and other space missions and large Earth surveys which are producing an enormous amount of extremely high quality still far, however, from being interpreted satisfactorily. In this context, star clusters are confirmed as powerful astrophysical laboratories to be used to test theoretical models.

“My group and I will be able to count on an enormous amount of work done by the community to which we belong. However, the ERC finances projects based on an element of novelty or a break with the past, especially where there are large problems that have been open for a long time, to which traditional techniques have not been able to give an answer so far, just like in our case” concludes Pancino. (by Andreana d’Aquino)