Nathan Bryon and Dapo Adeola have won the Waterstones Children’s Book Prize for their debut picture book Look Up!, about a black girl who dreams of becoming an astronaut.

The story explores the significance of role models, representation and the amount of time we spend using mobile devices.

Winners of the prize, now in its 16th year, are awarded £5,000 and a commitment by Waterstones to support their writing and illustrating careers.

The retailer’s expert booksellers voted on the 2020 entries in March but the announcement was postponed due to the coronavirus pandemic.

Actor and writer Bryon, whose writing credits include Rastamouse, Swashbuckle and Apple Tree House, wrote the story partly as a message to himself.

He said: “I was inspired to write Look Up! after walking around Hyde Park with my girlfriend. She wanted me to see the Peter Pan statue and I was too busy looking down at my phone, refreshing my emails.

“The book is a message to me to be more present, to Look Up! and see all the wonderful things that are around me, as my emails really aren’t that important.”

Illustrator Adeola was inspired by one of his nieces.

He said: “I tried to capture her curiosity and zest for knowledge in Rocket’s mannerisms as well as her innocently self-assured attitude to problem solving, traits that should be celebrated in both boys and girls.”

Florentyna Martin, Waterstones children’s buyer, said: “The mould of traditional picture book storytelling is redefined for a new era in this joyful and energetic tale; an inviting narrative plot is interspersed with nuggets of non-fiction, satisfying curious young minds with a multi-faceted experience away from screens.

“More than ever before, we are exploring non-fiction and inspirational characters at younger ages, and we champion Rocket’s boundless enthusiasm, curious nature and kind spirit as a hero for us all.

“She is a little person with big dreams, who has captured our hearts.”

Look Up! also won in the illustrated books category, while Liz Hyder’s Bearmouth won the older readers’ category and High-Rise Mystery by Sharna Jackson took the category for younger readers.