Substellar Companions and the Formation of Hot Subdwarf Stars
Geier, S. Heber, U. Tillich, A. Hirsch, H. Kupfer, T. Schaffenroth, V. Classen, L. Maxted, P. F. L. Ostensen, Roy Barlow, B. N. Marsh, T. R. Gansicke, B. T. Napiwotzki, R. O'Toole, S. J. Gunther, E. W.
Springer New York LLC
AIP Conference Proceedings vol:1331 pages:163-169
International Conference on Planetary Systems beyond the Main Sequence location:Bamberg, GERMANY date:AUG 11-14, 2010
We give a brief review over the observational evidence for close substellar companions to hot subdwarf stars. The formation of these core helium-burning objects requires huge mass loss of their red giant progenitors. It has been suggested that besides stellar companions substellar objects in close orbits may be able to trigger this mass loss. Such objects can be easily detected around hot subdwarf stars by medium or high resolution spectroscopy with an RV accuracy at the km s-1-level. Eclipsing systems of HW Vir type stick out of transit surveys because of their characteristic light curves. The best evidence that substellar objects in close orbits around sdBs exist and that they are able to trigger the required mass loss is provided by the eclipsing system SDSS J0820+0008, which was found in the course of the MUCHFUSS project. Furthermore, several candidate systems have been discovered.