Got a light?

Campfire Song

Scientists have discovered the coolest star ever found to emit radio waves, according to a new study published Thursday in The Astrophysical Journal Letters.

Per the study, at roughly 797 degrees Fahrenheit, the star in question — unceremoniously dubbed WISE J062309.94−045624.6 — is hotter than an oven, but cooler than a typical cigarette lighter flame. For contrast's sake: our Sun, a burning, bubbling, plasma-firing orb of nuclear fusion, has an estimated surface temperature of roughly 9929.93 Fahrenheit.

"In some cases, [stars] are cooler than the smoke that's rising off our campfire — I mean, that's inspiring," Kovi Rose, a doctoral candidate in astronomy at the University of Sydney and the study's lead author, told The New York Times. "It's inspiring and humbling to understand our place in the universe."

Song of Stars and Planets

That said, WISE J062309.94−045624.6 is a very different kind of star than our Sun. As the NYT explains, the lighter-like cosmic body is a brown dwarf, which is sometimes sadly referred to as a "failed star." As far as stars go, it's fairly small — smaller than Jupiter — and as a result, it doesn't have nearly as much gravitational pull as is needed to perform nuclear fusion.

A "brown dwarf is partway, in mass and temperature, between a star and a planet," Tara Murphy, an astronomy professor at the University of Sydney and a study co-author, told the NYT.

But because they can't perform nuclear fusion, brown dwarfs are dimly lit, and impossible to see with the naked human eye. So, rather than rely on traditional telescopes, the researchers instead relied on data from the Australian Square Kilometer Array Pathfinder — in addition to data from instruments including the MeerKat radio telescope in South Africa and the Australia Telescope Compact Array — to sift through radio waves emitted by stars' electromagnetic fields.

"Every band of that electromagnetic spectrum gives you a completely different window into the universe," Murphy told the NYT. "It's like a detective story."

It's not the coolest star ever found — as the NYT points out, that would be WISE J085510.83-071442.5, another brown dwarf. But this latest discovery could offer some fascinating insights into the varying magnetic fields of brown dwarfs, less than ten percent of which, per the NYT, are known to emit radio waves.

"Once we realized that it was a brown dwarf, yeah, it was definitely quite exciting," Rose told the NYT, "because then you kind of go down this rabbit hole of trying to figure out what the implications are, and what we can learn about the magnetic field properties."

More on stars: Scientists Attempt to Explain Star with Tentacle-like Arms

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