I do not know the criteria for earning the award.
I was in several severe air attacks and thought we should have received a Battle Star for three of them. However, we were awarded a Battle Star for only one, the massive air attack on Convoy UGS-40 on 11 May 1944.
You can go to the web site for Battle Stars at
www.BattleStarsAndNavalAwards.com or contact the author of the book I mentioned at:
Tamaroa@aol.com. (If it is still available).