Have checked several sources and have not found any reference to a Austin Light Artillery from Texas. Have found the Austin Light Artillery of Arkansas. Commanded by Capt. John T Trigg, it was formed in November, 1861 at Austin Ark. Later was also called the 9th Arkansas Battery. It served in northeast Arkansas, moved to central Kentucky with Hardee's forces. It was in the retreat from Bowling Green to Shiloh. This battery is believed to not have reformed in summer 1862 and disbanded. Could this be the Austin Light Artillery you seek? Both from neighboring Trans-Mississippi states