*****************       OGLE ALERT #1   ********************************


The Early Warning System has detected a microlens candidate in Baade's
Window field BW6:  BW6 167045 

The star was constant in 1992 and 1993 observing seasons with the mean
I-band magnitude 18.22, and sigma 0.039. It started brightening in the
middle of June 1994, and reached detection threshold of the EWS system
on July 8. Last observations suggest that star is slowly fading which
might mean a low amplitude (0.3 magnitude) short time scale event.


*********


1994 season  observations are listed below:

JD-2448000 i-mag   error

1439.91625 18.231  0.039
1440.87943 18.234  0.036
1465.85206 18.231  0.030
1466.89260 18.167  0.027
1468.87346 18.229  0.037
1469.86737 18.255  0.037
1513.75944 18.122  0.030
1514.68161 18.157  0.029
1515.68421 18.177  0.035
1516.66682 18.121  0.029
1516.81015 18.096  0.021
1516.89628 18.197  0.038
1518.66715 18.143  0.037
1518.81793 18.219  0.045
1521.77027 18.135  0.032
1522.75376 18.080  0.029
1534.64099 17.998  0.030
1535.65149 17.896  0.027
1536.58262 17.890  0.029
1537.73904 17.924  0.020
1538.71869 17.979  0.035
1539.62136 17.903  0.026
1541.58619 17.934  0.025
1543.55138 17.982  0.026
1543.69539 18.003  0.027
1544.59280 17.972  0.024
1544.75493 17.958  0.027
 
i color is instrumental one -- very close to the standard I. Error is
DoPhot photometry program error, approximately 1.4 -- 1.5 smaller than
the real error of observation.

*********

Preliminary fit of the theoretical microlensing light curve yields the
following parameters:

Time of maximum: JD  2449537
time scale:  13 days
Amplitude: 0.3 mag


********

Position of the candidate (2000.0):

RA= 18:03:45.1
DEC=-30:18:16.4

********

Colors in normal brightness:

V=19.80
V-I=1.59

********

The candidate has been probably detected around maximum light. However,
at this stage we cannot rule out possibility that it will brighten
more. We suspect that this is a microlensing event -- photometric
behavior is similar to detected earlier events, but we cannot rule out
possibility that we have found some unusual variable star. Any
additional observations, in particular spectroscopic and in other
photometric bands, would be very important. We'll post an update on
photometric behavior of the candidate in a few days. 

Postscript version of the finding chart (66 x 66 arc sec) and light
curve with theoretical fit are available via anonymous ftp from:
sirius.astrouw.edu.pl (148.81.8.1)

directory /ogle/ews/bw6

files:
167045.ps  -- light curve (updated daily till the star reaches normal
              brightness) 
fchart.ps  -- finding chart  ( North is up, E to the left. Star is
              marked by arrows. 66 x 66 arc secs).

We can e-mail both files on request.


Andrzej Udalski and Michal Szymanski 
Warsaw University Observatory