Saturday, 15 April 2017

A train wreck reborn

The Universe is filled with disaster. All stars will eventually die and some of them will even explode, blowing the planets that orbit them to smithereens. Entire galaxies are withering away because they're lacking the strength to revive star formation. Others are crashing into each other or absorbing smaller companions until they're utterly consumed. Even our seemingly infinite Universe is not eternal and most physicists currently agree that its expansion's accelerating and that it will continue to do so. All matter will eventually be dispersed so much that stars can no longer be formed and the existing stars will all die. Even black holes will disappear in the end since they emit mass through radiation (the so-called Hawking-radiation). The Universe will have no more energy and reach absolute zero temperature. A universal big freeze as it were.

But often these biblical calamities are not the end. NGC4449's a reasonably close dwarf galaxy (well... only 12 million lightyears away), similar in size to the Large Magellanic Cloud that's accompanying our Milky Way and which is a spectacular sight in our southern hemisphere. It can be found near the Cocoon Galaxy and has about the same apparent brightness, so accessible to all under a sufficiently dark sky. Just like the Cocoon, this little bugger's being influenced severely by its close neighbours, in this case an even smaller galaxy and a big globular cluster, both of which were invisible to me. They're perturbing NGC4449 with great force and deforming its entire structure. Let's face it, tidal forces have transformed it into a train wreck. But as you, my loyal readers, know very well, this calamity's actually reviving the Train Wreck Galaxy. I could clearly see many bright knots in it, regions of extreme star formation, much more than e.g. in the Cocoon. Thousands of new stars mean tens of thousands of new planets and probably a lot of new life to go with them. 

So let's enjoy this rebirth before the Univserse will eventually fade away. Well, we probably still have about a hundred trillion years before that happens. 

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