Kim Yong Sun (김용선), popularly known as Solar, is the leader and vocalist of the girl group 'MAMAMOO' under RBW Entertainment (formerly WA Entertainment). She is also a part of MAMAMOO's official subunit, 'MAMAMOO+'. She has her own YouTube channel, 'solarsido' (솔라시도) on which she uploads videos of herself, occasionally accompanied by guests, doing challenges and vlogs.
In 2015, Solar was on the show 'We Got Married' where she was paired with Eric Nam and also appeared on 'King of Masked Singer' as Sunflower in 2016. On December 2, 2018, Solar went on the KBS2 show 'Battle Trip' with Moon Byul to Hong Kong as part of episode 74. On September 25, 2021, she appeared and performed on KBS's show 'Immortal Songs 2' on its 525th episode. On October 2nd of the same year, she released a cover of the single "Something Special" by Jang Yeonjoo for the show 'Yoo Hee-yeol's Sketchbook'. Solar is also included as a judge of the wavve show 'VEILED MUSICIAN', which first broadcasted on September 22, 2023 at 7 PM KST.
Solar officially debuted as a soloist on April 23, 2020 with the single album "Spit It Out". She made her comeback with her first extended play on March 16, 2022, titled as "容 : FACE".
In 2022, Solar made her theatrical debut in the 2nd production of "Mata Hari". She was double-casted alongside Ock Joo-hyun for the titular role of "Mata Hari". The musical was announced by production company EMK Musical Company on April 6 with a teaser. The show premiered at the Charlotte Theater in Seoul on May 28 at 7 PM KST, and the performances lasted until August 15.