Dr. Marek Zawilski

Lodz, Poland
 
 

In the late evening of April 12,2003, a spectacular grazing occultation of the star eta Leonis (3.5 mag, double) could be observed in Poland.
After several failed trials, this time the observations could be performed in good weather conditions. Three independent teams of observers were located along the graze limit.  Several CCD cameras were used for recording the event. All geographical co-ordinated were established with the use of portable GPS instruments type Garmin.
Unfortunately, two circumstances turned out to be unfavourable :

* Close co-ordination of observers’ stations has not been made; as a consequence, some gaps appeared in the obtained lunar profile;

* Errors in the lunar profile caused “miss” for certain observers

Number of stations/observers/contacts at three locations were as following :

Location                         Leader                Stations                 Observers             Contacts
Wagrowiec                     A.Wrembel            4                            4                           11
Pabianice                       M.Zawilski            12                          22                          34
Tumlin                            L.Benedyktowicz  12                          13                          23
In total                                                       28                          39                          68
 

Only one contact was counted for a single event of the double star (see explanation below). So, total number of registered contacts is even greater.
The graze took place at lunar phase of 79%, waxing phase and at cusp angle 5o N.
The star was close double with its components of 4.1 and 4.6 mag. in ephemeridal separation of 0.1 seconds of arc at positional angle 93 degrees.
However, the components caused no remarkable stepwise events and only gradual dis- and reappearance could be noticed. Not instantaneous events clearly were seen on the video recordings but in few cases also were noticed by visual observes.
The D/R events lasted about 0.08-0.22 sec.
The observed lunar profile, although not recorded completely, distinctly reveals essential differences in relation to the predicted one.  The differences are substantial for every kind of predicted profile, i.e. Watts, Moonlimb and ACLPPP.
Because the observed profile is very coherent, the only conclusion drawn from the observations is that every predicted profile was incorrect and that the observation could improve it substantially.
 
 
 

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