###########################################################################
For convenience in addition to the images we give some information
stored in OGLE-I database on objects decribed in paper.ps.
PLEASE NOTE THAT ONLY PART OF THE INFORMATION IS IN STANDARD
PHOTOMETRIC SYSTEM. SOME FILES ARE DATA BASE OUTPUTS IN INSTRUMENTAL
SYSTEM.

Transformation from instrumental to standard VI system:

   V = v  + 0.032*(V-I) - 0.038
         +/-0.005      +/-0.015 

   I = i  - 0.018*(V-I) + 0.017
         +/-0.006      +/-0.021

 V-I =      1.047*(v-i) - 0.061
         +/-0.008      +/-0.019

###########################################################################

This directory (/ogle/subframes) contains:

README               -- this file
paper.ps.gz          -- a paper "Stellar Variability Background
                        in OGLE-I Microlensing Search" by P.R. Wozniak
                        and M. Szymanski describing this set of data
                        (photometry in standard VI)

field_number.tar.gz  -- a set of  101 x 101 pix subframes extracted from
                        each OGLE-I frame in the I band and centered on
                        microlensing events and variable stars described
                        in paper.ps (please note that tar file will open
                        to directory field_number named with the number
                        of the star in the database of I measurements
                        and containing fits files named after original
                        images with suffix "c" before .fts extension, which
                        means that for two stars in the same field only
                        directory name identifies where a particular frame
                        belongs)

frame_logs.tar.gz    -- catalogs of all frames for a given field in I and V
                        (field_i.log and field_v.log)
                        columns are:
                         1. sequential number
                         2. frame number as recorded by Data Acquisition
                            Program at LCO
                         3. heliocentric Julian Date of the mid-exposure 
                            (minus 2448000)
                         4. UT moment of mid-exposure
                         5. exposure time in seconds
                         6. air mass
                         7. average FWHM in pixels
                         8. average sky level in DN
                         9. number of objects measured by DoPhot
                        10. grade (A-E)

light_curves.tar.gz  -- I and V light curves of all stars described in paper.ps
                        (in standard VI)
                        (field_number_i.lc and field_number_v.lc)
                        columns are:
                         1. heliocentric Julian Date of the mid-exposure 
                            (minus 2448000)
                         2. magnitude
                         3. magnitude error
                         4. DoPhot type of object
                         5. flag (an indication of possible problem, 
                            see paper.ps for a reference)
                         6. grade (A-E)
                         
                         some files with V data are marked "N" before star 
                         number, which indicates that the object was not
                         detected on the template and is recorded in the
                         database of "new" objects, in which case column 5
                         is missing (see paper.ps for references to the
                         detailed description of the database and photometry)

info_[i,v].txt       -- database catalog records for stars from paper.ps
                        (instrumental vi photometry)
                        columns are:
                         1. position in the catalog
                         2. template coordinates x,y in pixels
                         3. sum of magnitudes
                         4. sum of magnitude errors
                         5. number of "good" points for which magnitudes
                            were summed
                         6. multiplicity of the object (number of the
                            independent measurements of the object from
                            different subframes, see a detailed description
                            of the database)
                         7. flag (1 - object multiple on the same subframe,
                            2 - object too close to the edge of the subframe,
                            3 - both of the above)

                         in case of "new" objects column 6. means byte offset
                         of the first record for the object in the *.dbn
                         database file in hexadecimal notation

                         the order of the stars in info_i.txt and info_v.txt
                         is the same so both files together serve as
                         cross identification between databases of I and V
                         measurements