Grimes: Elon Musk and musician welcome second baby - name explained, how many children does the Tesla CEO have

After naming their son X Æ A-Xii in 2020, the couple have given their second child an equally unusual name

In a recent interview with Vanity Fair, Grimes, whose real name is Claire Elise Boucher, revealed that she and Tesla CEO Elon Musk welcomed a second child into the world at the end of last year.

The announcement came about by accident as she had intended to keep their daughter a secret, however the plan was scuppered after the baby began crying loudly during the interview.

This is everything you need to know.

When did they have their daughter?

The pair welcomed their second child via surrogate at the end of last year, something which the singer revealed after opening up about her pregnancy with X Æ A-Xii, who she calls X, in 2020.

She said: “He was pressing on my nerves, so I kept collapsing. I took a few steps and collapsed.

In the interview, Grimes opened up about the toll that pregnancy had on her body (Photo: ROBYN BECK/AFP via Getty Images)

“It was kind of scary, because you don’t want to fall a lot when you’re eight months pregnant. So I would just crawl to the bathroom and crawl back or whatever.”

At one point during her pregnancy, she said that she thought she was dying.

Grimes said: “Like, I haemorrhaged. It was scary.”

So what’s her name?

Following on from naming their son X Æ A-Xii, Grimes and Musk have given their daughter a similarly unusual name.

The baby girl’s name is Exa Dark Sideræl, although she is called Y for short.

Exa is a reference to the supercomputing term exaFLOPS, which is the ability to perform 1 quintillion floating-point operations per second.

Dark refers to “the unknown”, Grimes explained: “People fear it but truly it’s the absence of photons. Dark matter is the beautiful mystery of our universe.

The couple have, predictably, given their daughter a very unique name (Photo: ROBYN BECK/AFP via Getty Images)

Sideræl, which is pronounced “sigh-deer-ee-el”, is what Grimes described as “a more elven” spelling of sidereal which is “the true time of the universe, star time, deep space time, not our relative earth time”, as well as a nod to her favourite Lord of the Rings character Galadriel.

As well as Y, Grimes and Musk also occasionally call her Sailor Mars, which is a reference to the Sailor Moon manga series.

In the interview, Grimes revealed that Exa Dark Sideræl was actually a compromise, and said that she had actually fought for the name Odysseus.

“A girl named Odysseus is my dream,” she said.

How many children does Elon Musk have?

While Grimes and Musk have two children together, Musk has a number of children from his previous marriage with Canadian writer Justine Wilson.

Musk and Wilson lost their first child together in 2002, Nevada Alexander Musk, when he died of sudden infant death syndrome at just 10 weeks old.

Elon Musk and son X Æ A-Xii. The Tesla CEO has seven children altogether (Photo: Theo Wargo/Getty Images for TIME)

The couple decided to pursue IVF and in 2004, twins Xavier and Griffin were born, followed by triplets Kai, Saxon and Damian in 2006.

Musk and Wilson divorced in 2008 after having been married for eight years, and they share custody of their five sons.

So are Grimes and Elon Musk back together?

The news of Grimes and Musk’s second child together may come as somewhat of a surprise for fans, as it had been somewhat confirmed by Musk himself that, towards the end of last year, that the two had split up.

In an interview with Time after being chosen for 2021 Person of the Year, Musk said: “Grimes and I are, I’d say, probably semi-separated.”

In early 2022, it had also been reported that Musk was in a relationship with Australian actress Natasha Bassett (Operation Buffalo, Hail, Caesar!).

However Grimes confirmed to Vanity Fair that the two were back together, in their own way.

The couple welcomed their first child together in 2020 (Photo: ANGELA WEISS/AFP via Getty Images)

She said: “I would probably refer to him as my boyfriend, but we’re very fluid. We live in separate houses. We’re best friends. We see each other all the time.

“We just have our own thing going on, and I don’t expect other people to understand it.”

She added that their relationship is “the best it’s ever been” and that they are planning on having more children together in the future.

“We’ve always wanted at least three or four [children],” she said.

Grimes also told the publication that she and Musk sometimes discussed whether she was a simulation created to be his companion, and that she often believed she was.

She said: “The degree to which I feel engineered to have been this, like, perfect companion is crazy.”

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