“Big Star” is a song about Lorde’s dog, Pearl, and how much she loved him.

In November 2019, Lorde sent an email to her fans where she revealed that Pearl had unfortunately passed away. In the email, she wrote about how Pearl changed her life:

Pearl came into my life in 2018, and almost immediately changed everything for me. As anyone who has had the pleasure of raising a dog can understand, my life grew exponentially. Pearl brought an immeasurable amount of joy and purpose into my world. Love vibrated all around us. I felt my life growing and swelling in healthfulness, this orb of contentment glowing around me and Pearl, and our family. We spent almost all our time alone together, him asleep under the piano as I played, or on the porch together, or in the park, where he became a blurry speck of gold in the green, far away.

In a June 2021 interview with The Guardian, Lorde also talked about how this influenced Solar Power as a whole:

Grief is a really transformative force. I’d never experienced it fully like that, and it makes you question everything. It overturns a lot. This record is about how precious life is, really.

In the song’s booklet, she wrote:

Pearl was under the piano when I started this. I had never loved anyone that much. I was trying to make sense of it. I probably never will.