But how did the massive star on the outskirts of the 30 Doradus Nebula get blasted away? There is no known mechanism that allows a star to travel at these speeds by itself, so astronomers studying the Hubble images believe there were another two stars implicit in sending the third to a lonely death.
30 Doradus (also known as the Tarantula Nebula) is a chaotic breeding ground for the most massive stars in the Large Magellanic Cloud, located about 170,000 light-years from Earth. In fact, several stellar heavyweights topping 100 solar masses (nearly the maximum mass for a star) are known to live there, so this nebula is an ideal place to study how and why these stars grow so big.
In such a fertile and dynamic stellar nursery, it's hardly surprising that some of these monsters cross paths from time to time. However, this is the first runaway star to be detected powering away from the nebula at such high speeds.
"These results are of great interest because such dynamical processes in very dense, massive clusters have been predicted theoretically for some time, but this is the first direct observation of the process in such a region. Less massive runaway stars from the much smaller Orion Nebula Cluster were first found over half a century ago, but this is the first potential confirmation of more recent predictions applying to the most massive young clusters." –Nolan Walborn, Space Telescope Science Institute in Baltimore.
Using the new Cosmic Origins Spectrograph (COS) that was installed during Hubble's Service Mission 4 (in May 2009), astronomers calibrated the instrument by studying this young massive star. Astronomers have known about the star for some time (since its original discovery in 2006 by astronomers using the Anglo-Australian Telescope at Siding Spring Observatory, Australia) and suspected it was a little out of place. It is located far from any other young blue stars in the R136 cluster, a sure sign that something was amiss.
The COS instrument confirmed this in July 2009 when it observed extremely hot stellar winds emanating from the star. This suggests the star was only one or two million years old, again, another piece of evidence that confirmed the rogue star's youth.