The Optical Gravitational Lensing Experiment. OGLE-III Long Term Monitoring of the Gravitational Lens QSO 2237+0305

TL;DR

This paper presents a decade-long, homogeneous photometric dataset of the gravitational lens QSO 2237+0305 from the OGLE survey, revealing unique microlensing activity and providing valuable data for the community.

Contribution

It provides the most extensive, calibrated long-term photometric monitoring data of QSO 2237+0305, combining OGLE-II and OGLE-III observations for the first time.

Findings

Revealed unique microlensing activity over a decade.

Provided a homogeneous, calibrated dataset for future studies.

Enabled community access to extensive photometric data.

Abstract

We present results of the long term monitoring of the gravitational lens QSO 2237+0305 conducted during the OGLE survey. Light curves of all four components of the lens obtained during the second phase of the OGLE project (OGLE-II; 1997-2000) are supplemented with the data collected in the OGLE-III phase in the observing seasons 2001-2006. Calibration procedures to tie the new OGLE-III data with already calibrated OGLE-II light curves are described. The resulting homogeneous OGLE data set is the most extensive photometric coverage of the gravitational lens QSO 2237+0305, spanning now one decade - the seasons from 1997 to 2006 - and revealing unique microlensing activity of this spectacular object. All photometric data of the gravitational lens QSO 2237+0305 collected by OGLE are available to the astronomical community from the OGLE Internet archive.