Jon Gosselin is celebrating his daughter Hannah and son Collin's first day of high school. The 42-year-old DJ and former TV personality sent off Hannah and Collin, two of his children with ex-wife Kate Gosselin, Monday on their first day as high school freshmen. Gosselin shared photos with Hannah and Collin on Instagram. Gosselin and his ex-wife are parents to 15-year-old sextuplets -- Hannah, Collin, Aaden, Alexis, Joel and Leah -- and 18-year-old twins, Cara and Mady. "FRESHMAN!!! 9th Grade Wow!!! I can't believe it!!! Good luck to Hannah and Collin this year!! Today is their first day of high school!!!!" Gosselin captioned the post. "I hope all my kids have a wonderful year in high school this year and have great experiences!!!" he added. "Love all of you!!!" Gosselin was awarded sole temporary custody of Collin in December. He told People the same month that Hannah also lives with him full-time. "The other four aren't talking to me, but they're talking to Hannah," Gosselin said of Aaden, Alexis, Joel and Leah, who live with Kate Gosselin. "It's what the kids want to do. If they don't want to talk to me, that's fine, as long as they keep up with their sibling connections." Gosselin's eldest daughters, Cara and Mady, meanwhile, graduated from high school in May. Kate Gosselin said the twins will attend college in the fall. "These girls are going places and I can't wait to see where they end up! Cara and Mady, I love you so very much and I'm just so so proud of YOU!" Kate Gosselin wrote on Instagram. Gosselin and his family came to fame on the TLC series "Jon & Kate Plus 8," which was renamed to "Kate Plus 8" following the pair's divorce. Kate Gosselin has also starred on the spinoff series "Kate Plus Date," which she said was an exciting but awkward experience.