In words spelled with aught and ought, the letters u & gh are silent, and the vowel is pronounced with the open ɑ/ɔ sound.
(The sounds /ɑ/ and /ɔ/ are pronounced the same in the West Coast variety of American English).
taught = tot
bought = bot
caught = cot
More examples
thought
/thɔt/
He thought about it all afternoon.
brought
/brɔt/
She brought watermelon to the picnic.
fought
/fɔt/
Princess Leia fought valiantly.