Stellar (스텔라, often stylized as STELLAR) is a four-member girl group under The Entertainment Pascal. They officially debuted on August 28, 2011 on SBS's Inkigayo by performing their first single "Rocket Girl". Shortly after the release, Lee Seul and JoA left and were replaced by Minhee and Hyoeun. In May 2017, Soyoung joined as their fifth member. On August 23, 2017, their agency announced that original members Gayoung and Junyool would "graduate" from the group on the 31st after deciding not to renew their contracts. On August 25, their agency announced that they would be adding newest member Youngheun to the group, and the group would continue as four members.