PLEASE cite the following paper when using the data or referring to these OGLE results: Zebrun et al. (2001), Acta Astron., 51, 317.




1. The Catalog

Here we present the catalog of the variable stars found in the LMC and SMC data obtained during four years of OGLE-II project duration (January 1997 - November 2000). The variables were found with the Difference Image Analysis (DIA) software. The catalog is divided into two sections. The DC section contains FITS reference images (obtained by co-adding 20 best frames for each field) and DoPHOT photometry of all stars on those images. The AC section contains light curves in flux and magnitude of over 68000 detected variable stars. For convenience we present short instruction of catalog usage.

2. The Method

There are basically two methods of analysis of photometric CCD observations. The first method is implemented in in Daophot (1987) and DoPHOT packages (1993). This packages use all information about star flux to measure brightness.
In early nineties a new method was developed (Image Substraction Method - IMS). In this method substracted images are analysed. Only variable part of star flux is measured - AC signal. Additionally we measure constant signal on reference frame - DC signal. The combination of AC and DC signal gives us light curve of star. The quality of results are far better than those obtained with DoPHOT or Daophot packages especially in crowded fields.
To create this Catalog we used the implementation of the IMS introduced by Christophe Alard and Robert Lupton and called Difference Image Analysis. Full description of method and photometric pipeline can be found in papers by Woźniak and by Żebruń Soszyński & Woźniak.

3. The Data

We present the analysis of 21 LMC fields and 11 SMC fields. The cover 4.62sq.deg and 2.42sq.deg of LMC and SMC respectively. Typically, there are ~400 I-band data points, and ~30 V and B-band data points. The DIA method used only I band OGLE II data. In the I band we detected in total ~2x10^7 objects. The DIA analysis provided almost ~7x10^4 candidates for variable stars. For comparision the catalog contains also the OGLE results of photometry for I, V and B bands.

4. Inctruction of usage

The catalog main window is divided into two sections. The left panel contains links to different parts of the catalog. The contents of the left window can vary depending on the information we want to display. There are two distinct sections DC and AC of the catalog. Below there are graphical diagrams showing how to browse through our catalog.

DC CATALOG FIELD SELECTION - CLICK TO VIEW WINDOW EXAMPLE
DC CATALOG FIELD DETAILS - CLICK TO VIEW WINDOW EXAMPLE

AC CATALOG TABLE - CLICK TO VIEW WINDOW EXAMPLE
AC CATALOG STAR DETAILS - CLICK TO VIEW WINDOW EXAMPLE

The detailed description can be found in paper describing our catalog (see References).

5. References

If You are not satisfied with this brief information please use one of these references.

Stetson, Peter B., 1987, PASP, 99, 191 - Daophot description
Schechter, Paul L., Mateo Mario, Saha Abhijit, 1993, PASP, 105, 1342 - DoPHOT description
Alard, C. and Lupton, R. H. Astroph. Journal 1998 no. 503 page 325 - description of image substraction method
Woźniak, P., 2001, Acta Astron., 44, 227 - description of DIA
Żebruń K. Soszyński I. and Woźniak P. R., 2001, Acta Astron. 51, 303, astro-ph/0110612 - description of DIA (the method used to create this catalog)
Żebruń K. Soszyński I. et. al., 2001, Acta Astron. 51, 317, astro-ph/0110623- the paper describing contents of this catalog


6. Availability of the Catalog

The data presented in this WWW catalog are also available from OGLE anonymous FTP servers:

//sirius.astrouw.edu.pl/ogle/ogle2/dia/ (in Poland)

We tried to remove all errors and omissions from the catalog. However if You encounter any problems please send a message to a following e-mail adresses:

soszynsk@astrouw.edu.pl


Now You can enter the Catalog.