Sunday, January 17, 2016

Bugs and Spiders

So the exploration flotilla left Shapley 1 yesterday and began its trek towards the next waypoint, the mighty Lagoon Nebula, also known as Messier 8. What lay before us were some 1,000 light years and the approach towards the Sagittarius Gap. I could have taken the direct road, speeding towards the Lagoon, but I decided to take a detour and poke around some of the deep sky objects that lay, well, not exactly along the way, but in the exploration corridor the fleet was going to take anyway. 

I always wanted to see and travel to the Northern Jewel Box (NGC 6231). It is dubbed the V945 Scorpii Cluster by explorers and it is magnificent to behold even from afar. The cluster is very young and is thought to have formed directly from material from the Lagoon. However, there was enough time in the cluster for the first stars to collapse already, leaving behind the occasional black hole or neutron star.

En route to the cluster also lies a very interesting structure: The bipolar planetary nebula of NGC 6302, dubbed the Bug Nebula. You should definitely pay it a visit. The nebula allegedly formed after a very large star collapsed into a Wolf-Rayet object. The former star really must have been at the upper level to still produce a nebula ‘peacefully’ instead of having gone nova and blowing stuff apart much more violently. The star’s magnetic field acted as a containment for the ejected material and that – simply speaking – is why we see the nebula in its bipolar ‘hourglass’ shape. Like I said, go there and write a postcard to your loved ones.

If afterwards you are still not fed up with nebulae (before heading to the Lagoon Nebula) there is still the Red Spider Nebula (NGC 6537). It is some thousand light years away from NGC 6530 and the Bug Nebula, but hey, no rush! The Spider is a worthy sight. Contrary to the Bug Nebula the Spider does not seem to have a central star. In ancient astronomy texts there are references to a White Dwarf but so far all astrometric methods of locating it in terms of navigational data have failed. Maybe the dust disc in the centre is just too dense for astrometric pinpointing. What it has in common with the Bug Nebula (and in fact with many planetary nebulae) is its bipolar structure. The central star blew off much of its outer shells and the magnetic fields or maybe the gravitational influence of a massive binary star have forced the stellar ejecta into its peculiar form. Nice to behold and absolutely interesting for studying plasma physics.

These are just three of the more prominent examples of the in-betweens when travelling from Shapley 1 coreward. It is an area of space dominated by active molecular regions that still hold enough gas and dust to produce many stars. In fact, the whole area is classified as a H-II region and those nebulae in it are just the colourful and most visible hot spots of it, much like the Orion or Carina Molecular Complex. 

Space repeats itself, but now it’s time for the Lagoon and its beauty.

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