@article{AlcaldeMediavillaMoreauetal.2002, author = {Alcalde, D. and Mediavilla, E. and Moreau, O. and De Rop, Y. and Barrena, R. and Gil-Merino, Rodrigo and McLeod, B. A. and Motta, V. and Oscoz, Alejandro and Serra-Ricart, M.}, title = {QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring}, year = {2002}, abstract = {We present VR observations of QSO 2237+0305 conducted by the Gravitational Lensing International Time Project collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2.56 m Nordic Optical Telescope at Roque de los Muchachos Observatory, La Palma (Spain). The point-spread function (PSF) fitting method and an adapted version of the ISIS subtraction method have been used to derive the VR light curves of the four components (A-D) of the quasar. The mean errors range in the intervals 0.01-0.04 mag (PSF fitting) and 0.01-0.02 mag (ISIS subtraction), with the faintest component (D) having the largest uncertainties. We address the relatively good agreement between the A and D light curves derived using different filters, photometric techniques, and telescopes. The new VR light curves of component A extend the time coverage of a high-magnification microlensing peak, which was discovered by the OGLE team.}, language = {en} } @article{PugaAlcaldeBarrenaetal.2001, author = {Puga, E. and Alcalde, D. and Barrena, R. and Mediavilla, E. and Motta, V. and Munoz, J. A. and Oscoz, Alejandro and Serra-Ricart, M. and Gil-Merino, Rodrigo and Goicoechea, Luis Julian and Lewis, G. f and Libbrecht, C. and Moreau, O. and Surdej, J. and Wambsganß, Joachim}, title = {Daily monitoring of the gravitational lens QSO 2237+0305 at the Nordic Optical Telescope}, isbn = {0-7923-6974-2}, year = {2001}, language = {en} }