Astron. Astrophys. 343, 1025-1029 (1999)

Gravitational lensing by rotating stars

J.F. Glicenstein

DAPNIA/SPP, CEA Saclay, F-91191 Gif-sur-Yvette, France

Received 15 July 1998 / Accepted 6 November 1998

Abstract

The equations giving the position of the images of a point source by a rotating point lens are derived by a new, elementary method. It is shown that only two of the three images are visible. It is argued that the projection of the angular momentum of the lens star on the lens plane can be measured if the lens is a rapidly rotating early type star. This is achieved by performing a series of astrometric measurements of the position of the images.

Key words: gravitation stars: rotation cosmology: gravitational lensing

Correspondence to: glicens@hep.saclay.cea.fr

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Lensing by a non-rotating point-like star
• 3. Time delay induced by stellar rotation
• 4. Number of images
• 5. Time delay
• 6. Misalignement of the images
• 7. Measurement of the angular momentum of the rotating lens
• 8. Conclusion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: March 1, 1999
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