The OGLE project started in 1992 and the Galactic Bulge has been selected as the first target. Observations are carried out at the Las Campanas Observatory, Chile (LCO) which is operated by the Carnegie Institution of Washington.
First part of the project, concluded in 1995, was carried out using the 1m Swope telescope.
We expect a substantial increase of the data flow and detection rate of microlensing events with a new 1.3m Polish telescope built in Las Campanas Observatory by the Warsaw University. The telescope produced its first light in 1996 and regular observations started in January 1997. The telescope will be dedicated for the long term, photometric surveys of the large areas of the sky.
During the first part of OGLE project nineteen microlensing events have been found in the direction of the Galactic Bulge including one event most likely caused by a binary lens. You can find more info about these events here:
| OGLE #1 | OGLE #2 | OGLE #3 | OGLE #4 | OGLE #5 | OGLE #6 | |||||
| OGLE #7 | OGLE #8 | OGLE #9 | OGLE #10 | OGLE #11 | OGLE #12 |
In 1994 observing season a new feature is implemented in the OGLE data system: the "Early Warning System" (EWS). It allows the detection and identification of microlensing events in real time. Thus, the system makes it possible to reschedule observations to obtain the best coverage of a microlensing event while it unfolds, as well as to arrange follow-up photometric and/or spectoscopic observations from other observatories.
First ever ongoing microlensing event was caught on July 8, 1994. The EWS detected a microlens candidate in Baade's Window field BW6. The event was a low-magnification (0.3 mag) short-lasting (t0=13 days) event. First OGLE ALERT info was sent to interested astronomers for follow-up observations. Second ongoing event was detected on August 20, 1994. The star from Baade's Window, BW5 I 83758, underwent microlensing. The time scale was about 20 days.
In 1995 season 6 more events, that is OGLE 14 - 19, have been discovered so far with the EWS system (beginning of August 1995).
The huge amount of the collected photometric data necessary for microlensing search provides also an unique observing material for conducting independent side projects. Results of the first of them on the structure of our Galaxy have already been published. The huge catalog of periodic variable stars is available from OGLE archive: anonymous ftp from astro.princeton.edu, directory /ogle/var_catalog
There is also a special WWW interface to the DATABASE of OGLE results.
The observing time when the Galactic Bulge is not visible or seeing is too large for observations of the dense Bulge fields is used for additional observational side projects. In 1992 clusters of galaxies were observed for supernovae, in 1993 globular clusters and Sculptor dwarf galaxy were observed for variable stars.
Another project being pursued when the bulge is not observable is a systematic study of the newly discovered Sagittarius dwarf galaxy. Deep photometry of the galaxy and light curves for newly-discovered variables in Sgr are also available.
Here is the OGLE team at Las Campanas Observatory, Chile in June 1992
Here you can find a few pictures of the Las Campanas Observatory located at the 2300 m altitude in Chilean Andes Mountain at the southern edge of the huge Atacama desert.
More goodies and pictures is available from the anonymous ftp on astro.princeton.edu.
Bibliography of the OGLE-I papers can be found here.