On the presence and absence of disks around O-type stars

¹ Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland, UK e-mail: jsv@arm.ac.uk
² The School of Physics and Astronomy, EC Stoner Building, The University of Leeds, Leeds LS2 9JT, UK
³ Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA
⁴ School of Physics, University of Exeter, Exeter EX4 4QL, UK
⁵ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

Received: 1 June 2009
Accepted: 24 July 2009

Abstract

As the favoured progenitors of long-duration gamma-ray bursts, massive stars may represent our best signposts of individual objects in the early Universe, but special conditions seem required to make these bursters. These are thought to originate from the progenitor's rapid rotation and associated asymmetry.