A list of all double and multiple stars
With the help of data from the Gaia astrometry mission, a complete catalogue of all known double and multiple stars in the vicinity of the sun up to a distance of 33 light years was created. This provides interesting information about the frequency of such systems.
According to everything we know, our sun is a single star. However, this makes it more of a minority, as many other stars are members of a binary or even multiple star system. A research team led by Javier González-Payo at the Spanish Complutense University of Madrid has now used data from the Gaia astrometry satellite to look at the immediate vicinity of our sun up to a distance of 33 light years or 10 parsecs. The group compiled a complete list of all stars and brown dwarfs centred around the Sun in this region of space and published it in the journal «Monthly Notices of the Royal Astronomical Society» (MNRAS).
In total, the catalogue lists 424 known objects. Of these, 215 stars and brown dwarfs belong to a total of 92 systems with one or more other objects. 68 of these 92 systems are binary stars, 19 are triple star systems. In addition, three quadruple star systems and even two systems containing a total of five stars were found - a real rarity.
The orbital periods of the stars around each other range from one day to several million years. Around 41 per cent of all known stars in the region of space under consideration with more than half a solar mass are part of a binary or multiple star system. In contrast, stars and brown dwarfs with less than a tenth of the mass of the sun are only nine per cent likely to have one or more companions. For the first time, González-Payo's team was thus able to make a quantitative statement about the stars in our immediate cosmic neighbourhood, from which conclusions can be drawn about the formation history of some of these systems.
The quintuple star systems are particularly rare. One of these is Alula Australis in the constellation of the Great Bear, from which we are 27 light years away and which is divided into several components. Two sun-like stars, which orbit their common centre of gravity in around 1.8 years, form component A. Component B also consists of a close binary star with a period of only four days. Together with component A, they orbit their common centre of gravity in around 60 years. Component C, a single brown dwarf, orbits the system at a large distance. The system WDS J16555-0820 is even more complex: its main component is a double star with a period of 2.96 days, which orbits the common centre of gravity with star component B in just 627 days. Much further out are components C and D, known as Wolf 629 and VB 8, which have extremely long orbital periods.
Spectrum of Science
We are a partner of Spektrum der Wissenschaft and want to make well-founded information more accessible to you. Follow Spektrum der Wissenschaft if you like the articles.
Experts from science and research report on the latest findings in their fields – competent, authentic and comprehensible.
From the latest iPhone to the return of 80s fashion. The editorial team will help you make sense of it all.
Show all
