Spectrosc. of the circumstellar gas of WD1145+017

We present a series of observations, five epochs over a year, taken with Keck and the VLT, which for the first time show variability of circumstellar absorption in the gas disk surrounding WD1145+017 on timescales of minutes to months.

Circumstellar absorption is measured in more than 250 lines of 14 ions among 10 different elements associated with planetary composition, e.g., O, Mg, Ca, Ti, Cr, Mn, Fe, and Ni. Broad circumstellar gas absorption with a velocity spread of 225km/s is detected, but over the course of a year blueshifted absorption disappears, while redshifted absorption systematically increases. A correlation of equivalent width and oscillator strength indicates that the gas is not highly optically thick (median {tau}~2).