Question: A teen idol is a celebrity with a large teenage fan-base, often teen idols are actors or musicians, like Ariana Grande and who?
Context: In Japan, a junior idol (ジュニアアイドル , junia aidoru ) , alternatively chidol (チャイドル , chaidoru ) or low teen idol (ローティーンアイドル , rōtīn aidoru ) , is primarily defined as a child or early teenager pursuing a career as a photographic model.  Generally, this means gravure, or "cheesecake", fully clothed shots; but, junior idols can, and some do, eventually enter the AV industry.  Child actors, musicians, and J-pop singers (whose musical genre is often termed idol pop) can also be considered junior idols and are often featured in photobooks and image DVDs. A teen idol is a celebrity with a large teenage fan-base.  Teen idols are generally young but not necessarily teenaged.  Often teen idols are actors or musicians, like Ariana Grande and Niall Horan, but some sports figures also have an appeal to teenagers.  Some teen idols began their careers as child actors, like Lindsay Lohan. "Popular Song" is a song by Lebanese-British recording artist Mika, released as the second single in the United States from his third studio album, "The Origin of Love".  The song features American singer and actress Ariana Grande and is included on her debut album, "Yours Truly".  The track was written by Mika, Priscilla Renea, Mathieu Jomphe and Stephen Schwartz, and produced by Mika and Greg Wells.  The pop version featuring Ariana Grande was produced by Jason Nevins. Ariana Grande-Butera (born June 26, 1993), better known as Ariana Grande ( ), is an American singer and actress.  She began her career in 2008 in the Broadway musical "13", before playing the role of Cat Valentine in the Nickelodeon television series "Victorious", and in the spinoff "Sam & Cat" until 2014.  She has also appeared in other theatre and television roles and has lent her voice to animated television and films. Confessions of a Teen Idol is an American reality series that began airing on VH1 on January 4, 2009 and concluded on February 22, 2009.  It ran for eight episodes.  The series was hosted and produced by former teen idols Scott Baio and Jason Hervey.  The show was filmed in the same house used to film "". "Break Free" is a song by American singer Ariana Grande featuring Russian-German music producer Zedd.  It was the second single from Grande's sophomore studio album "My Everything" (2014).  It premiered on July 2, 2014 on "Total Ariana Live", MTV's revival of "Total Request Live", and was released later that day.  Musically, the song explores EDM and electro genres, a musical departure for Grande, whose discography is primarily composed of pop and R&B. Yours Truly is the debut studio album by American singer and actress Ariana Grande.  It was released on September 3, 2013, by Republic Records.  Incorporating R&B, "Yours Truly" was influenced by Whitney Houston, Amy Winehouse, Christina Aguilera and Mariah Carey, amongst other of Grande's greatest idols.  Grande describes the album's first half as a "throwback" to the R&B music of the 1990s, and the second half being "very unique and very special that I've sort of written" which is completely original.  On the album, Grande co-wrote six out of the twelve tracks.  Contribution by Harmony Samuels, Kenneth "Babyface" Edmonds, Patrick "J. Que" Smith and "Victorious" co-star Leon Thomas III, as well as others, handling the production on the album.  Grande recorded a number of songs on this album over a three-year period.  The collaborations are with Big Sean, Mika and Mac Miller, in addition to The Wanted's Nathan Sykes, who features on the song "Almost is Never Enough" which was also included on .  Occasionally, the album dips into other genres such as adult contemporary music and dance music. Thomas Lee "Tommy" Brown (born May 1, 1986), also known as Tommy Brown or TB Hits, is an American recording artist, musician, Multiplatinum record producer and songwriter.  Tommy currently lives in LA and was born and raised in Pittsburgh, Pennsylvania.  He has received awards from ASCAP, and was Grammy  nominated.  He has scored multiple chart topping albums while working with Ariana Grande on her debut #1 album Yours Truly, and her second #1 album My Everything, lastly, Grande's 3rd studio album, Dangerous Woman charting #2 on Billboard 200.  Brown has also collected production credits for three songs on Grammy-award winning artist Meghan Trainor's second album, Thank You.  Brown's upcoming releases are DJ Khaled's next single "Forgive Me Father" feat Trainor & Wale, and Macy Gray's single "Sugar Daddy" feat Andre 3000.  Tommy Brown is also a music producer.  He has produced for many prominent artists including Ariana Grande, Travis Scott, Chris Brown, Black Eyed Peas (which gained him a Grammy nomination in 2010), T.I, Jennifer Lopez, Fifth Harmony, Pia Mia, Macy Gray, Jhene Aiko, Big Sean, Meghan Trainor, Victoria Monet, Meek Mill, Ludacris, Ray J and Gorilla Zoe.  He learned from production greats Roy "Royalty" Hamilton and Rodney Jerkins of Darkchild, while working alongside them and eventually creating a team of his own and producing with them. Phillip Hill is an American bass and guitar player.  He was born in Nashville, Tennessee, on November 3, 1972.  He has been involved in several pop punk bands, including Teen Idols, Screeching Weasel, The Independents, Common Rider, Even in Blackouts, The Queers and the Kobanes.  Hill is also a skilled vocalist.  He has worked extensively as a recording engineer.  His audio engineering credentials appear on numerous albums with a wide spectrum of musical styles, from the pop-punk sounds of bands such as Anti-Flag, Rise Against, Screeching Weasel and his own band, Teen Idols, to the heavy, "death metal" sounds of Human Filleted and Catatonic Atrocity, as well as the country-roots, folksy-blues sounds of The Clayton Miller Blues Band and Appalachian String Band. This is a list of Japanese idols; a type of celebrity in Japan.  The word "idol" is almost always used to refer to a young woman, although there a significant number of male idols.  The following list includes both female and male idols as well as both solo idols and idol groups.
Answer: Niall Horan