I purchased some Bitcoin on Coinbase with the intent of sending it to Poloniex. I accidentally sent my Bitcoin to my Bitcoin Cash address on Poloniex. Is it possible to retrieve the Bitcoin or is it gone?
is it confirmed yet? if it doesn't have any confirmation you could still save your bitcoin by trying double spend attempt
by any chance you could re-create new transaction on coinbase or export privkey so you can create tx with other wallet or tool