I am sure you guys have researched the topic extensively, but here is what I found:
It's weird that there is soo much interest in this banana tree, yet there is very little information about it on the internet. The only article I found discussing it's origin was written by guess who....An employee(probably owner) of TyTy. I even recognized his name from the Amazon feedback section...He had posted positive reviews for TyTy as if he were a customer!!!
Here is the article:
thePhantomWriters.com / thePhantomWriters.org:: Article: The Modern Soft Yellow Banana Evolved From The Cooking Banana As The Number One Fruit In The World
I have seen some other sites mention the Texas Star, but only briefly as a cold hardy banana. The link posted by somoeone else earlier describes Texas Star as a dwarf orinoco... Since no credible source for the tree seems to be available...I think TyTy has been pulling a fast one for years. If there truly was this miraculous cold hardy banana...why wouldn't other nurseries follow suit? Do a little digging and you'll see that ALL the sites with info and/or Texas Star banana plants for sale are run by TyTy.