May 3, 2014
Drifting Through the Void
Name something that you fear.
How about the thought of oblivion? Of being lost within absolute nothingness. Of being cast into the void for all time, with nothing save your own thoughts for company and so sound save for your own panicked breath. This is the sort of fate I would wish upon no one, not even those I thought of as my most hated enemy (if you do not mind me being a little dramatic). I find the very concept of such a fate haunting, one reserved for the darkest of science fiction and mystical fantasy. Or is it? Unfortunately for HVGC-1, it is not.
HVGC stands for “hypervelocity globular cluster.” Recently discovered by astronomers, HVGC-1 is the first of its kind, a globular cluster – a collection of thousands of starts all crammed together into a ball that is a few dozen light-years across – cast out into the endless void of space by its home galaxy, M87. It was only by chance that researchers even discovered HVGC-1, as the team studying M87 has been studying doing so for several years. This research included sorting various targets by color so that they could separate stars and galaxies from globular clusters. Once that was done, they used the Hectospec instrument on the MMT Teslescope in Arizona to examine these discovered clusters in greater detail. Using a computer, they calculated the speed of every single cluster, with any oddities the computers did not recognize being studied closer to identify them. Most were just glitches in the system, but not HVGC-1. Much to the researchers surprise, there really was a cluster out there flying through space at more than two million miles per hour.
M87 is a truly massive galaxy. A super-giant, this elliptical galaxy is believed to weigh as much as six trillion suns and could be the most massive galaxy in the known universe. Since the discovery of HVGC-1, researchers have speculated that at the center of M87 there may actually be two super-massive black holes rather than just one. It is believed that this could be the result of a long-ago collision between two galaxies which then merged to form a single, massive elliptical galaxy. Scientists also believe that our own galaxy, the Milky Way, may also meet such a fate as it collides with the Andromeda galaxy in a few billion years. Scientists have already deemed this combined galaxy “Milkomeda.”
It is believed that the insane velocity of HVGC-1 is because of the two black holes in M87’s core. Drifting too close to them, HVGC-1 was flung out from the core like a slingshot, dooming this globular cluster to be forever lost to the void. Its discovery, the first of its kind, is astonishing. According to Nelson Caldwell of the Harvard-Smithsonian Center for Astrophysics, “Astronomers have found runaway stars before, but this is the first time we’ve found a runaway star cluster.”
It’s amazing to think of just how this celestial entity was tossed out of its galaxy like a fastball thrown by the most powerful pitcher in the cosmos. Though its fate is not one I, or anyone I know, would like to share in, it’s fascinating to learn that such things are out there. Our universe is truly vast and filled with marvels beyond measure. Each discovery, such as with HVGC-1, just makes us all the more eager to learn more.
Image Credit: David A. Aguilar, Harvard-Smithsonian Center for Astrophysics