Sun-like stars devour planets in their orbit, study indicates

In planetary systems formed by stars similar to the Sun, however that present severe dynamic processes that cause reconfigurations in their architecture, some planets may have been devoured by the host star.

An international team on astronomers led by Lorenzo Spina, perform Istituto Nazionale di Astrofisica (INAF), on Padua, Italy, electronic including Jorge Melndez, perform Institute on Astronomy, Geophysics electronic Atmospheric Sciences of a University on So Paulo (IAG -USP) studied the chemical composition of stars over photovoltaic type in over a hundred binary systems, in order to identify signatures of eventually swallowed planets. This article was published today (16) in the journal Character Astronomy.

In a binary system, like two stars thus formed the parte perform even electronic materials, therefore, should be chemically identical. However, when a planet falls on some star, it is dissolved in the outer perform inside stellar region, called the convective area, electronic can modify the composition of that region, increasing the content of chemical elements, called refractory, which therefore abundant in rocky planets . In stars whose signatures indicate engulfment on planets therefore observed larger quantities of electronic lithium over iron than their twin star performs binary system, says Melndez Agncia Fapesp.

According to a researcher, u lithium stars destroyed zero inner dieses, but preserved zero materials that make up operating system planets. Therefore, some abnormally high abundance of this chemical element in some star may indicate that planetary material has been swallowed up by it.

The study was based on observations about 31 binary pairs, therefore, on 62 stars, obtained with a HARPS zero telescope spectrograph over 3.6 meters perform Observatory over La Silla, operated by Western European The southern area of ​​Observatory (ESO). Operating system data collected in the regional area were complemented with previous results, which were not recorded in the specialized literature. dry, solitary electronic distant from a light pollution, which presents the 2 darkest night sky of an Earth.

This was the largest sample ever studied on similar stars in binary systems electronic operating system results showed that at least a quarter of these sun-like stars devour their own planets. The finding suggests that some significant fraction 2 planetary systems had a very dynamic past, unlike our Photo voltaic System, which preserved some ordered architecture, says Melndez. , Lorenzo Spina, the search for planets similar to Earth like looking for some needle zero haystack. However, this result opens the possibility of using abundances of certain chemical elements to identify stars with comparable perform Sol composition. Stars deficient in so-called refractory elements are more likely to host structures analogous to our Solar System.

A well-studied binary system 16 Cygni, situated at some distance about 69 light years from an Earth. The system formed by two yellow Sun-like stars an rings, 16 Cygni A electronic 16 Cygni T. Electronic perhaps encompasses Also some red dwarf star. It is estimated that 16 Cygni A electronic 16 Cygni Udemærket are separated by some distance from 860 UA . For comparison purposes, the distance between the electronic Sun is the so-called Heliopause, which constitutes the farthest boundary perform System Sun, estimated between 110 electronic 160 UA. Despite the enormous distance separating the two twin stars, the strongly eccentric orbit of a larger planet performs than Jupiter orbiting the star 16 Cygni W perhaps sony ericsson is due to the gravitational perturbation produced by the star 16 Cygni A.

Interesting to note that the component 16 Cygni A , that zero has no planets detected, overabundant in refractory elements, one that suggests that perhaps this star has not swallowed planets, comments Melndez.

The research was supported by a FAPESP, through about Thematic project High-precision spectroscopy: first stars to planets, coordinated by Melndez.

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