Answer:
no, his parents were married ........now wait a second
First you have to have some legal basis for an opinion, best to check first with Black's Law Dictionary, under BASTARD... an illegitimate child; a child born before the lawful marriage of its parents; ie born out of lawful wedlock
Since Barrack Obama Sr. was a married man from Kenya having gone through his tribal ceremony in his village and blessed with a child and having lived with that Kenyan wife he was then considered in the eyes of his world to be married.
Obama Sr. never obtained a divorce document from that marriage so he was a married man when he enpregnanted the 17 year old classmate three months after she had arrived at the Univ. of Hawaii. To have married Stanley Ann Dunham in 1960, which there is no record of, then that would have been bigamy which is a criminal offence and statuatory rape of girl under the age of consent.
Stanley Ann Dunham never lived with Obama Sr. who lived in the campus dormitories, she lived at home until just before the delivery at some other place than the two hospitals in Honolulu.
Barack Obama Jr. was definitely born out of lawful wedlock and falls into the category of an illegitimate child, and most likely indubitably doubly so. It is reputed that our 15th President James Buchanan was also a bastard prresident so what is the big deal.