Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | Winner | Jockey | Trainer | Owner | Time | Purse |
| --- | --- | --- | --- | --- | --- | --- |
| 2013.0 | London Bridge | Mike Smith | Jo Hughes | Eastwind Racing & Martha Trussell | 2:58.32 | $500,000 |
| 2012.0 | Calidoscopio (ARG) | Aaron Gryder | Guillermo Frenkel Santillán | Stud Dona Pancha | 2:57.25 | $500,000 |
| 2011.0 | Afleet Again | Cornelio Velasquez | Robert E. Reid, Jr. | Kasey K Racing Stable | 3:00.39 | $500,000 |
| 2010.0 | Eldaafer | John Velazquez | Diane Alvardo | IEAH Stables and Mansour Albaroudy | 2:59.62 | $500,000 |
| 2009.0 | Man of Iron | Johnny Murtagh | Aidan O'Brien | Derrick Smith/ Susan Magnier / Michael Tabor | 2:54.11 | $500,000 |
| 2008.0 | Muhannak | Pat Smullen | Ralph Beckett | Richard Pegum | 2:28.24† | $500,000 |
Question:
What was the purse when the trainer was Aidan O'Brien?
Answer:
$500,000