Wednesday, May 02, 2012

Hyper-velocity Ejected Star

Now here is another truly strange character - Ejected Stars or Rogue Stars if you like. These are stars that astronomers say are or were ejected from the MW galaxy.

It would seem however that this is an extremely difficult thing to do. Here is an excerpt of the Science Daily article that gives you an idea just HOW difficult.

  • the primary mechanism (for ejecting stars from the milky-way galaxy) that astronomers have come up with that can give a star the two-million-plus mile-per-hour kick it takes requires a close encounter with the super-massive black hole at the galaxy's core.
It seems that it is so difficult and thus so rare that only sixteen hyper-velocity stars have been verified, and even though they have enough speed to eventually leave the Milky Way all together, they are still "inside" the galaxy.

However this may not be the case completely. Here is another excerpt.

  • Vanderbilt astronomers report in the May issue of the Astronomical Journal that they have identified a group of more than 675 stars on the outskirts of the Milky Way that they argue are hyper-velocity stars that have been ejected from the galactic core.
Very strange indeed.  Here is the link to the rest of the Science Daily article

Picture shows Four runaway stars plowing through regions of dense interstellar gas and creating bright bow waves and trailing tails of glowing gas. The stars in these NASA Hubble Space Telescope images are among 14 young runaway stars spotted by the Advanced Camera for Surveys between October 2005 and July 2006 (from

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