Although five gold rings would be perhaps more appropriate, here’s a somewhat late Christmas tree on the fifth day of the festival:
The Christmas Tree Nebula, aka NGC 2264
Unlike the names of some nebulae, the ‘Christmas Tree Nebula’ is one which actually fits pretty well. Both the shape and the colour used to represent the light in this image are evocative of a tree, and it’s even complete with baubles - hot new stars forming from gas collapsing out of the clouds in the nebula.
A Norway Spruce for comparison; click for credit.
And there are further parallels to be drawn: evergreen trees are used in various religious and secular winter celebrations to symbolise colour, growth and renewal in a season of cold and darkness. A nebula, with its swirls of super-heated gas stretching into the dim emptiness of space and its core of bright young stars, seems like a pretty good symbol as well. And like a tree which feeds on the compost of its departed relatives, these new stars are congealing out of gas which has already been enriched by the death of previous generations of stars. Gas formed at the Big Bang was almost entirely composed of just hydrogen and helium, the lightest elements in the universe. But stars can fuse these together into heavier elements in their nuclear-furnace cores. So it’s only the explosion of old stars, spewing their products back into space, that allows new stars - or their solar systems - to start their lives with such elements.
Thus all the heavier elements here on Earth, including the oxygen and carbon that are essential to make up our Christmas trees and ourselves, are remnants of stellar explosions billions of years ago in deep space and have passed through a process of star formation like that currently going on in the Christmas Tree Nebula.
How’s that for recycling?
It’s awesome! There must, too, be at *least* one star at the top of that thing.
Yes, of course. How could I remember the baubels but forget the star on top?