Larry Hagman, who plays J.R. in the television series "Dallas," became a grandfather Wednesday. The baby girl was named after her great-grandmother, Hagman's mom, actress Mary Martin . . .
Singer Michael Jackson is taking a break, according to Don King, the Victory Tour promoter. "He goes on but he can't keep his tempo constantly. He is taking some time out to experiment with new dance steps, new songs, new ideas." Michael's sister Janet Jackson is also taking a break, but not from work. She says in the August issue of Essence magazine that her 10-month marriage to musician John DeBarge has been annulled . . .
Sen. Edward Kennedy arrived in Dublin yesterday to open the Special Olympics for the mentally handicapped. During his two-day visit, he will meet with Prime Minister Garret FitzGerald to discuss Anglo-Irish efforts to end the civil unrest in Northern Ireland . . .
Former president Jimmy Carter and his wife Rosalynn will visit Greece later this month to meet with Prime Minister Andreas Papandreou, President Christos Sartzetakis and Foreign Minister Ioannis Charalambopoulos.
Ruth Lawrence isn't your average 13-year-old. Yesterday she graduated from Oxford University with a degree in mathematics. She completed the degree in just two years instead of the normal three and received a special prize in her major . . . .