The time delay of Q0957-+-561 A,B from 10 years of optical monitoring

  • R. Schild
II. Observations
Part of the Lecture Notes in Physics book series (LNP, volume 360)


Brightness monitoring of Q0957+561 A,B since its discovery in 1979 permits a time delay of 1.1 years to be established with 99 percent confidence. A best value for the time delay is now 404 days. Comparison of the brightness records shifted for the time delay shows an important discrepancy which we attribute to microlensing by a star or stars in the lens galaxy.


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Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • R. Schild
    • 1
  1. 1.Center for Astrophysics CambridgeUSA

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