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The recent Hubble data revealed the misfit to be a young runaway, likely no morę than a few million years old. sińce very massive stars have relatively short life spans.

In addition. archivcd Hubble pictures madę with visible light show that the star lics in a cavity being carved by its sprint through the ncbula. The cavity’s shape suggests that the star is traveling away front the R136 cluster. (Related: "Hubble Tclcscopc at 20: NASA Astronomers' Top Photos.")

According to thcory. there are two main ways stars can get booted out of their home clusters. A ncarby supernova can give the star a kick. or a complex gravitational dance bctwccn neighboring stars—called dynantical interaction—can send a star packing.

The R136 cluster is thought to be no morę than two million years old, which nteans it's far too young for any supemova to have occurred yet, said Raghvendra Sahai. an astronomer at NASA's Jet Propulsion Laboratory in Pasadena. Califomia. who wasn't involved in the study.

(Related: '"Rcncgadc' Stars Tearing Across Univcrsc. Hubble Shows.")

Instead. study co-author Lennon said. "we think that a massive star has essentially intcracted with a massivc binary pair of stars" in a cosmic version of billiard balls. "This thcn caused one of the stars to get ejected in a slingshot effect."

Stars ejected by supemovae have been seen before. but 30 Dor 016 is the first known candidate for a star that's been kickcd out of a "dance party," the study authors report in a paper published online May 5 in the Astronlnsical Journal Letters.

The runaway won't get too much farther. though. Given its size and current age. the star should go supcmova somctime within the next half million years.

Runaway a Clue to Fabled Stellar Titans

According to JPL's Sahai. "if we believc the authors argument that [30 Dor016| is a runaway star and that it has been ejected front R136, then it is a vcry valuablc discovery of the process of dynantical interaction."

Undcrstanding dynamical interaction can give researchers new insight into the early days of the universe.

Thats because. in addition to bootinga few youngsters. suchcosmic billiard games mighl cause stars that don't Ieave the nest to collide and merge into superntassive stars, Computer ntodels hint.

Thcsc theorctical titans could grow to be as much as 150 to 300 limes the sun's mass. Such giants are thought to havc been common in the early universe. so Lennon and his team hope to use Hubble to track down modem vcrsions of the fabled monsters.

(See "Early Universe's First Stars Spied in Distant Galaxies.")

"If we can find thcsc supermassivcs." Lennon said. "then it makes the Tarantula Nebula and its cluster a unique laborator)' for testing the kinds of stars that fomied just after the big bang.”