Geoffrey Marcy, an acclaimed astronomer and leader in the hunt for planets around other stars, has been found guilty of violating the sexual harassment policies of the University of California, Berkeley, where he holds the Watson and Marilyn Alberts Chair in the Search for Extraterrestrial Intelligence.

In June, the university concluded that Dr. Marcy had engaged in inappropriate behavior with students, including groping them, kissing them and touching or massaging them. He was told that subsequent violations would leave him subject to sanctions, as the vice provost, Janet Broughton, said in a letter, “that could include suspension or dismissal.”

Because of the confidential nature of such investigations, Dr. Marcy’s colleagues at Berkeley, which has been shaken by discrimination lawsuits under Title IX recently, and elsewhere did not know of the investigation until this past week when Buzzfeed broke the story and Dr. Marcy posted a letter of apology on his University of California website page.

“While I do not agree with each complaint that was made,” he wrote, “it is clear that my behavior was unwelcomed by some women. I take full responsibility and hold myself completely accountable for my actions and the impact they had. For that and to the women affected, I sincerely apologize.”