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Variable emission from a gaseous disc around a metal-polluted white dwarf

Wilson, D.J.; Gänsicke, B.T.; Koester, D.; Raddi, R.; Breedt, E.; Southworth, J.; Parsons, S.G.

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D.J. Wilson

B.T. Gänsicke

D. Koester

R. Raddi

E. Breedt

S.G. Parsons


We present the discovery of strongly variable emission lines from a gaseous disc around the DA white dwarf SDSS J1617+1620, a star previously found to have an infrared excess indicative of a dusty debris disc formed by the tidal disruption of a rocky planetary body. Time series spectroscopy obtained during the period 2006–2014 has shown the appearance of strong double-peaked Ca?II emission lines in 2008. The lines were weak, at best, during earlier observations, and monotonically faded through the remainder of our monitoring. Our observations represent unambiguous evidence for short-term variability in the debris environment of evolved planetary systems. Possible explanations for this extraordinary variability include the impact on to the dusty disc of either a single small rocky planetesimal, or of material from a highly eccentric debris tail. The increase in flux from the emission lines is sufficient that similar events could be detected in the broad-band photometry of ongoing and future large-area time domain surveys.


Wilson, D., Gänsicke, B., Koester, D., Raddi, R., Breedt, E., Southworth, J., & Parsons, S. (2014). Variable emission from a gaseous disc around a metal-polluted white dwarf. Monthly Notices of the Royal Astronomical Society, 445(2), 1878 -1884.

Journal Article Type Article
Acceptance Date Sep 8, 2014
Online Publication Date Oct 14, 2014
Publication Date Dec 1, 2014
Publicly Available Date May 26, 2023
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1538-3881
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 445
Issue 2
Pages 1878 -1884
Keywords circumstellar matter, stars, individual, SDSS J1617+1620, planetary systems, white dwarfs
Publisher URL


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