A Gaseous Metal Disk Around a White Dwarf
B. T. Gänsicke,*
T. R. Marsh,
J. Southworth,
A. Rebassa-Mansergas
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines constrains the outer disk radius to just 1.2 solar radii. The likely origin of the disk is a tidally disrupted asteroid, which has been destabilized from its initial orbit at a distance of more than 1000 solar radii by the interaction with a relatively massive planetesimal object or a planet. The white dwarf mass of 0.77 solar mass implies that planetary systems may form around high-mass stars.
Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
* To whom correspondence should be addressed. E-mail: boris.gaensicke{at}warwick.ac.uk
