A planetesimal orbiting within the debris disc around a white dwarf star

Manser, C. J.; Gansicke, B. T.; Eggl, S.; Hollands, M.; Izquierdo, P.; Koester, D.; Landstreet, J. D.; Lyra, W.; Marsh, T. R.; Meru, F.; Mustill, A. J.; Rodriguez-Gil, P.; Toloza, O.; Veras, D.; Wilson, D. J.; Burleigh, M. R.; Davies, M. B.; Farihi, J.; Gentile Fusillo, N.; De Martino, D.; Parsons, S. G.; Quirrenbach, A.; Raddi, R.; Reffert, S.; Santo, M. D.; Schreiber, M. R.; Silvotti, R.; Toonen, S.; Villaver, E.; Wyatt, M.; Xu, S.; Zwart, S. P.

doi:10.1126/science.aat5330

Many white dwarf stars show signs of having accreted smaller bodies, implying that they may host planetary systems. A small number of these systems contain gaseous debris discs, visible through emission lines. We report a stable 123.4-minute periodic variation in the strength and shape of the Ca II emission line profiles originating from the debris disc around the white dwarf SDSS J122859.93+104032.9. We interpret this short-period signal as the signature of a solid-body planetesimal held together by its internal strength.

A planetesimal orbiting within the debris disc around a white dwarf star / Manser, C. J.; Gansicke, B. T.; Eggl, S.; Hollands, M.; Izquierdo, P.; Koester, D.; Landstreet, J. D.; Lyra, W.; Marsh, T. R.; Meru, F.; Mustill, A. J.; Rodriguez-Gil, P.; Toloza, O.; Veras, D.; Wilson, D. J.; Burleigh, M. R.; Davies, M. B.; Farihi, J.; Gentile Fusillo, N.; de Martino, D.; Parsons, S. G.; Quirrenbach, A.; Raddi, R.; Reffert, S.; Santo, M. D.; Schreiber, M. R.; Silvotti, R.; Toonen, S.; Villaver, E.; Wyatt, M.; Xu, S.; Zwart, S. P.. - In: SCIENCE. - ISSN 0036-8075. - 364/2019:6435(2019), pp. 66-69. [10.1126/science.aat5330]