Astrophysics

Comets hint at cosmic encounter

Journal name:
Nature
Volume:
505,
Page:
134
Date published:
DOI:
doi:10.1038/505134a
Published online

Researchers have discovered a second comet belt in Fomalhaut, a bright, triple-star system that is already known to host an exoplanet and a bright comet belt around its primary star, Fomalhaut A (pictured).

Grant Kennedy at the University of Cambridge, UK, and his colleagues used data from the Herschel Space Observatory to find the second belt, which surrounds the system's least-massive star, Fomalhaut C. The discovery of two such bright comet belts around stars in the same system is rare, and suggests that the two stars had a close encounter that increased collision rates within each debris disk: colliding comets generate large amounts of dust and ice that would make the comet belts look brighter. Such a stellar interaction could also explain the elliptical orbits of Fomalhaut A's exoplanet and comet ring.

ALMA (ESO/NAOJ/NRAO); VISIBLE LIGHT IMAGE: NASA/ESA/HST

Mon. Not. R. Astron. Soc. 437, 26862701 (2014)

Additional data