Originally Posted by mxp2004

The call here by your opponent appears justified by the pot odds. After the flop, he has top pair plus a flush draw. Thus, he has 13 outs (9 hearts, 2 remaining 8s, and 2 other JavaScript).

With two cards to come, he'll make his hand about 48% of the time, and so the pot needs to lay him only a little better than even money to make this call. Since you stated that there were several limpers in this pot already after the flop, it's likely that he had the required odds.

You might have considered a pot-sized raise on the flop, and then pushed on the turn. A lot of players will call an all-in on the flop with a good draw, but will fold to a big bet on the turn when they have only one more card to make their hand. Note also that the pot odds needed for a player to continue to chase a draw on the turn are doubled, again because the player can expect only 1 more card instead of two. Thus, chances are that a call which is correct on the flop is a huge mistake on the turn.

15 outs, there are 3 jacks left.