In one of the most complex cosmic dances astronomers have yet spotted, three rings of gas and dust circle a trio of stars.
The star system GW Orionis, located about 1,300 light-years away in the constellation Orion, includes a pair of young stars locked in a close do-si-do with a third star making loops around both. Around all three stars is a broken-apart disk of dust and gas where planets could one day form. Unlike the flat disk that gave rise to the planets in our solar system, GW Orionis’ disk consists of three loops, with a warped middle ring and an inner ring even more twisted at a jaunty angle to the other two.
The bizarre geometry of this system, the first known of its kind, is reported in two recent studies by two groups of astronomers. But how GW Orionis formed is a mystery, with the two teams providing competing ideas for the triple-star-and-ring system’s birth.
In a Sept. 4 study in
Science, astronomer Stefan Kraus of the University of Exeter in England and colleagues suggest that
gravitational tugs and torques from the triple-star ballet tore apart and deformed the primordial disk. But in a May 20 study in the
Astrophysical Journal Letters, Jiaqing Bi of the University of Victoria in Canada and colleagues think that
a newborn planet is to blame.
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