Saturday, 23 December 2017

IC2087: When dust lights up

This may sound a bit odd, but most of our Universe is actually invisible to our eyes. When we look up at the night's sky and admire that mesmerising blanket of millions of stars, we only see things that emit light, i.e. stars and gas clouds that are heated up so much that they start glowing. But this is only a small percentage of all matter that surrounds us. The so-called dark matter is, indeed, invisible because usually we can't see it in a Universe that is essentially dark. 

And yet, every now and then we can catch a glimpse of all the dark dust and gas that's floating through space. When a cloud of this dark matter drifts in front of a bright stellar background, for instance, or when it reflects the light of nearby stars. In the case of IC2087, we observe both.

On the border between Taurus and Auriga there's a gigantic dust cloud, merely 700 light-years distant and denominated as Barnard 22, which blocks the light of all the stars that lie behind it. Just point your telescope in that direction and you'll agree that there are only very few stars to be seen. Even with my binoscope the field of view looked strangely empty. In the middle of all that darkness, however, you may find the bright patch which is the protagonist of this blog post. IC2087 is a reflection nebula, i.e. that this cloud merely reflects the light of stars that are embedded in it. Careful study of this cloud with infrared telescopes has not only revealed its main light source, but also that this nebula contains a lot of embryonic stars. These baby stars haven't really lit up yet and therefore the nebula remains difficult to see, for the moment. But soon fusion will kick in in the star's cores and the gas and dust will be heated up. Probably, within a couple of hundreds of thousands of years, this nebula will become a spectacular stellar nursery, brighter than the Orion Nebula. 

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