The North Celestial Tower : If you climbed to the top of this 13th century stone tower, it looks like you could reach out and touch the North Celestial Pole, the point at the center of all the star trail arcs. The well-composed image with scattered meteor streaks was recorded over a period of five and half hours as a series of 45 second long exposures spanning the dark of the night on July 7/8. The exposures were made with a digital camera fixed to a tripod near Marathon, Greece, planet Earth. Of course, the graceful star trails reflect the Earth’s daily rotation around its axis. By extension, the axis of rotation leads to the center of the concentric arcs in the night sky. Convenient for northern hemisphere night sky photographers and celestial navigators alike, the bright star Polaris is very close to the North Celestial Pole and so makes the short bright trail in the tower’s central gap. via NASA

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Record-Breaking Galaxy Cluster Confirms Dark Matter Universe

“But this new cluster is just 2.6 billion years old, and seems to be undergoing the very transition where a collection of galaxies falls into a bound structure for the first time, from a protocluster to a true galaxy cluster. This marks the first time astronomers have ever detected such an event: of the exact moment that a protocluster transitions to a true cluster. The fact that so many total galaxies (seventeen!) were discovered localized together at the same redshift (z=2.506) was a big hint, but the final piece of evidence came from the X-rays, where the diffuse emission engulfing the entire set of objects shows, beyond a shadow of a doubt, that this really is a galaxy cluster!”

There was once a time early on in the Universe where there were no stars, no galaxies and no clusters of galaxies at all. While stars and galaxies form very early on, after only tens or hundreds of millions of years, it takes billions of years for the first clusters to form. Yet even if we were to look back into the Universe’s past up to ten billion years, the clusters we see are already well-evolved and quiet. We had never seen a set of galaxies fall in and actively form a cluster before. We’d never seen the protocluster/cluster transition before. And we’d never found one from when the Universe was between two and three billion years old: when our dark matter theory predicts the first great clusters ought to form. Until, that is, now.

Come see how the Chandra X-ray observatory just found a record-breaking cluster that confirms our greatest picture of the Universe’s history!

Newborn stars are forming in the Eagle Nebula. This image, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars. At each pillars’ end, the intense radiation of bright young stars causes low density material to boil away, leaving stellar nurseries of dense EGGs exposed. The Eagle Nebula, associated with the open star cluster M16, lies about 7000 light years away. The pillars of creation were imaged again in 2007 by the orbiting Spitzer Space Telescope in infrared light, leading to the conjecture that the pillars may already have been destroyed by a local supernova, but light from that event has yet to reach the Earth.

Object Names: Pillars Of Star Creation

Image Type: Astronomical

Credit: J.Hester, P. Scowen (ASU), HST, NASA

Time And Space