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New VR magnification ratios of QSO 0957+561
L. J. Goicoechea, R. Gil-Merino, A. Ullan +5
We present VR magnification ratios of QSO 0957+561, which are inferred from the GLITP light curves of Q0957+561A and new frames taken with the 2.56m Nordic Optical Telescope about…
GLITP Optical Monitoring of QSO 0957+561: VR Light Curves and Variability
Aurora Ullan, Luis J. Goicoechea, Jose A. Munoz +6
The GLITP collaboration observed the first gravitational lens system (QSO 0957+561) from 2000 February 3 to 2000 March 31. The daily VR observations were made with the 2.56-m Nordi…
A Large Brightness Enhancement of the QSO 0957+561 A Component
A. Oscoz, D. Alcalde, M. Serra-Ricart +2
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…
QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring
D. Alcalde, E. Mediavilla, O. Moreau +12
We present VR observations of QSO 2237+0305 conducted by the GLITP collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2.56 m Nordic Optical T…
Detection of the 2175ÅExtinction Feature at z=0.83
V. Motta, E. Mediavilla, J. A. Munoz +6
We determine the extinction curve in the z_l=0.83 lens galaxy of the gravitational lens SBS0909+532 from the wavelength dependence of the flux ratio between the lensed quasar image…
'Round the Clock Observations of the Q0957+561 A,B Gravitationally Lensed Quasar
Wesley N. Colley, Rudolph E. Schild, Cristina Abajas +20
An observing campaign with 10 participating observatories has undertaken to monitor the optical brightness of the Q0957 gravitationally lensed quasar for 10 consecutive nights in J…