A Large Brightness Enhancement of the QSO 0957+561 A Component

Abstract

We report an increase of more than 0.2 mag in the optical brightness of the leading image (A) of the gravitational lens Q0957+561, detected during the 09/2000 -- 06/2001 monitoring campaign (2001 observing season). The brightening is similar to or even greater than the largest change ever detected during the 20 years of monitoring of this system. We discuss two different provisional explanations to this event: intrinsic source variability or microlensing (either short timescale microlensing or cessation of the historical microlensing). An exhaustive photometric monitoring of Q0957+561 is needed until summer of 2002 and during 2003 to discriminate between these possibilities.

arXiv comment13 pages including 3 figures and 1 table. Accepted for publication in ApJ Lett

References in corpus (8)

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Cited by in corpus (9)

• Measuring Microlensing using Spectra of Multiply Lensed Quasars
• A New Microlensing Event in the Doubly-Imaged Quasar Q0957+561
• New database for a sample of optically bright lensed quasars in the northern hemisphere
• Revealing the structure of the lensed quasar Q 0957+561: I. Accretion disk size
• The dark halo of the main lens galaxy in QSO 0957+561
• New VR magnification ratios of QSO 0957+561
• Peculiar Transverse Velocities of Galaxies from Quasar Microlensing. Tentative Estimate of the Peculiar Velocity Dispersion at $z\sim 0.5$
• A 5.5-year robotic optical monitoring of Q0957+561: substructure in a non-local cD galaxy
• GLITP Optical Monitoring of QSO 0957+561: VR Light Curves and Variability