European Southern Observatory (ESO) European Association for Astronomy Education (EAAE) Observatoire de Paris Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) Astronomical Institute of the Academy of Sciences of the Czech Republic European Science & Technology Week 2004    Visit the websites of the VT-2004 organisers

Index

 
  Results of the AU in real time from the whole set of measurements

 
You will find below the results of the calculation of the AU with the database of observations of contacts on June 18, just after the event and on July 10 at the closure of the experiment. The data were slightly more numerous and improved

In this table you get the values for each contact:

  • The value of the average distance of the Earth from the Sun (astronomical unit, AU).
  • The value of the dispersion.
  • The shift from the exact value of the AU.
The last line of the table, show the average value of the whole set of measurements.

Values using the database as it was on June 18

Nb timings Mean AU (km) Dispersion (km) Shift (km)
 
T1 722 149908018 2062405 310148
T2 1139 149076728 4878994 521142
T3 1336 149438938 1409362 158932
T4 1170 149840793 4620163 242923
 
All 4367 149529684 3638485 68186


Values on July 10 at the closure of the database

Nb timings Mean AU (km) Dispersion (km) Shift (km)
 
T1 732 149706234 5897344 108364
T2 1182 148969317 6471011 -628553
T3 1382 149333921 4257810 -263949
T4 1217 149715198 6240004 117328
 
All 4513 149401633 5714889 -196237


Observers´ location maps

Graphics

The plots below show the evolution of the online calculation of the AU, when observations arrived. Some stepsin these plots seem amazing but are easily explained.
At the begining, the AU changes quickly because of the small number of observations. Then, it converges towards the true value : the number of the "good" observations "well situated" on Earth increases. The steps are the signature of new observations either "good and well situated on Earth" (it makes the plots converging towards the true value) or "bad and badly situated on Earth" (it makes the plots escaping from the true value). This last occurence arrived when values are entered in the database in order to see their influence in the calculation of the AU (observers are making tests).


Remarks on the online calculation of the Astronomical Unit