[x]

It is possible that Obama's parents weren't married when he was born. He's said in his memoir that he never looked too closely into the matter for fear of what he might discover.

But so far as I can find out, he went by the name "Barry Obama" in high school -- no "Dunham" and no "Soetero." He did start using the name "Barack" in college, but that could have been his given name anyway: there are certainly plenty of schoolchildren who call themselves by their nicknames rather than what they were born with.

FWIW, maybe somebody in Hawaii can get copies of The Oahuan, the Punahou School yearbook, for the late 1970s.

[Bubba Ho-Tep]

It is possible that Obama's parents weren't married when he was born

According to the divorce decree, they were married on Feb. 2, 1961. So she was pregnant at the time.