NL20 SH Speed T9s, Flop Straight MWP

IPoker, $0.10/$0.20 No Limit Hold'em Cash, 6 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

SB: $23.77 (118.9 bb)
BB: $21.11 (105.6 bb)
UTG: $26.87 (134.4 bb)
Hero (MP): $20.98 (104.9 bb)
CO: $21.95 (109.8 bb)
BTN: $20.20 (101 bb)

Preflop: Hero is MP with T 9
UTG folds, Hero raises to $0.60, CO folds, BTN calls $0.60, SB folds, BB calls $0.40

Flop: ($1.90) Q 8 J (3 players)
BB checks, Hero bets $1.40, BTN calls $1.40, BB calls $1.40

Turn: ($6.10) A (3 players)
BB checks, Hero bets $4.60, BTN raises to $9.80, BB folds, Hero??

Preflop: I usually open this from the MP.

Flop: Hit the nuts, so betting for value.

Turn: KT beats me now. Still, I'm cbetting for value again, but then the BTN decided to raise. I believe he might have two pairs or sets sometimes. What should I do there?

BTN: 25/18/25/33/2,5/699 (VPIP/PFR/IP_FtFlopCB/IP_FtTurnCB/AF/H)