PokerStars No-Limit Hold'em, $0.05 BB (7 handed) - Poker Hand Converter from PokerConverter.com

saw flop

MP2 ($6.02)
CO ($9.49)
Button ($10.54)
Hero (SB) ($5.05)
BB ($2.93)
UTG ($6.42)
MP1 ($11.56)

Preflop: Hero is SB with K, Q
UTG calls $0.05, MP1 calls $0.05, MP2 calls $0.05, 2 folds, Hero calls $0.03, BB checks

Flop: ($0.25) 8, Q, J (5 players)
Hero bets $0.24, 2 folds, MP1 calls $0.24, MP2 calls $0.24

Turn: ($0.97) A (3 players)
Hero bets $0.50, MP1 raises to $1.80, 1 fold, Hero folds

Total pot: $1.97 | Rake: $0.09

You need to call 1.30 into a pot of 3.17 which is 2.4:1.
He looks like he hit that ace for sure, meaning you have at least 9 flush outs and 3 additional straight outs. If you don't think he has a queen or 88's here you also have 2 trip outs. That gives you 14 outs, in which case you need 2.3:1 to call. That means a call in this scenario would be slightly profitable. If you think he could already have a straight with KT then you have to discount that assessment slightly. There is about $3 behind in effective stacks which could also go into the decision making since he is likely (but not definitely) going to be willing to put the rest of his stack in.

Sooooo, the short answer would be that you should call there.

Grunch: Why are we betting this turn?

Is this a definite check-call?

I think so - b/f is bad and b/c is bad too. Straights, sets and 2 pair are abundant and fds aren't and the only Fd is AT which now beats you