Astronomers have discovered a very rare system of five connected stars. The quintuplet consists of a pair of closely linked stars – binaries – one of which has a lone companion; it is the first known system of its kind. The pair of stars orbit around a mutual centre of gravity, but are separated by more than the distance of Pluto’s orbit around the Sun. BBC reports:
The findings have been presented at the UK National Astronomy Meeting in Llandudno. The unusual system lies 250 light-years away in the constellation Ursa Major. It was discovered in data gathered by the SuperWASP (Wide Angle Search for Planets) project.
This uses relatively small and low-cost cameras in the Canary Islands and South Africa to image much of the sky every few minutes.
Measurements of the brightness of individual stars are, over years, assembled into light curves – plots of brightness against time. When the stars pass in front of one another, they produce a regular pattern of pairs of dips in the light curve.