Exoplanet, I dub thee Fortitudo. And you Hypatia, and you Tadmor and you Orbitar.

A public contest to name cosmic objects came to an end on Tuesday, when the International Astronomical Union announced new monikers for 14 stars and 31 exoplanets. The names are intended as approachable replacements for the astronomical designations originally given by scientists.

For example, the first sun-like star spotted with an orbiting planet is known as 51 Pegasi, and its planet 51 Pegasi b. Their new IAU-given names are Helvetios and Dimidium, respectively. Helvetios refers to a Celtic tribe from the Middle Ages, while Dimidium is the Latin word for “half”, a play on the planet’s mass measuring about half that of Jupiter. Both names were selected by the Astronomical Society of Luzern in Switzerland.


The first exoplanets ever discovered, which orbit pulsar PSR 1257+12, are now known as Poltergeist, Phobetor (a Greek god of nightmares) and Draugr (a fictional undead creature).

Fomalhaut b, possibly the first exoplanet imaged directly, will be called Dagon, a Semitic deity that’s half man and half fish.

Some objects were give names in honour of a religious or cultural tradition, such as Fafnir, a mythological Norse dwarf; Chalawan, a crocodile king from Thai folklore; and Meztli, an Aztec goddess of the moon.

Chasing windmills

Others followed a particular theme. Six stars and planets were named by the Royal Netherlands Association for Meteorology and Astronomy for famous people of science like Galileo Galilei, Tycho Brahe, and Hans Lippershey, a spectacle-maker credited with building the first refracting telescope. Another five received names in honour of Miguel de Cervantes’s famous novel The Ingenious Gentleman Don Quixote of La Mancha, submitted by the Planetarium of Pamplona in Spain.

“I’m fascinated to know whether the astronomical community will adopt or ignore these names,” says Greg Laughlin at the University of California, Santa Cruz, who has set up a page on prediction site Metaculus for people to weigh in with their best guesses.

Jason Wright, an astronomer and astrophysicist at Pennsylvania State University, doesn’t expect the new names to catch on. The IAU’s contest didn’t involve many members of the exoplanet community, he says, and academic journals may not take note of the results of a public outreach event.

“Only time will tell if astronomers adopt these names,” says Wright. “My sense is that we are so used to calling it 51 Peg b, that it would be difficult and confusing to change now.”

Image credit: IAU/L. Calçada